blob: cbba511a34a505f68581b62367ff78bdc01cd92a [file] [log] [blame]
//===-- DWARFExpression.cpp -------------------------------------*- C++ -*-===//
//
// 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 "lldb/Expression/DWARFExpression.h"
#include <inttypes.h>
#include <vector>
#include "lldb/Core/Module.h"
#include "lldb/Core/Value.h"
#include "lldb/Core/dwarf.h"
#include "lldb/Utility/DataEncoder.h"
#include "lldb/Utility/Log.h"
#include "lldb/Utility/RegisterValue.h"
#include "lldb/Utility/Scalar.h"
#include "lldb/Utility/StreamString.h"
#include "lldb/Utility/VMRange.h"
#include "lldb/Host/Host.h"
#include "lldb/Utility/Endian.h"
#include "lldb/Symbol/Function.h"
#include "lldb/Target/ABI.h"
#include "lldb/Target/ExecutionContext.h"
#include "lldb/Target/Process.h"
#include "lldb/Target/RegisterContext.h"
#include "lldb/Target/StackFrame.h"
#include "lldb/Target/StackID.h"
#include "lldb/Target/Thread.h"
#include "Plugins/SymbolFile/DWARF/DWARFUnit.h"
using namespace lldb;
using namespace lldb_private;
static lldb::addr_t
ReadAddressFromDebugAddrSection(const DWARFUnit *dwarf_cu,
uint32_t index) {
uint32_t index_size = dwarf_cu->GetAddressByteSize();
dw_offset_t addr_base = dwarf_cu->GetAddrBase();
lldb::offset_t offset = addr_base + index * index_size;
return dwarf_cu->GetSymbolFileDWARF()->get_debug_addr_data().GetMaxU64(
&offset, index_size);
}
// DWARFExpression constructor
DWARFExpression::DWARFExpression(DWARFUnit *dwarf_cu)
: m_module_wp(), m_data(), m_dwarf_cu(dwarf_cu),
m_reg_kind(eRegisterKindDWARF), m_loclist_slide(LLDB_INVALID_ADDRESS) {}
DWARFExpression::DWARFExpression(lldb::ModuleSP module_sp,
const DataExtractor &data,
DWARFUnit *dwarf_cu,
lldb::offset_t data_offset,
lldb::offset_t data_length)
: m_module_wp(), m_data(data, data_offset, data_length),
m_dwarf_cu(dwarf_cu), m_reg_kind(eRegisterKindDWARF),
m_loclist_slide(LLDB_INVALID_ADDRESS) {
if (module_sp)
m_module_wp = module_sp;
}
// Destructor
DWARFExpression::~DWARFExpression() {}
bool DWARFExpression::IsValid() const { return m_data.GetByteSize() > 0; }
void DWARFExpression::SetOpcodeData(const DataExtractor &data) {
m_data = data;
}
void DWARFExpression::CopyOpcodeData(lldb::ModuleSP module_sp,
const DataExtractor &data,
lldb::offset_t data_offset,
lldb::offset_t data_length) {
const uint8_t *bytes = data.PeekData(data_offset, data_length);
if (bytes) {
m_module_wp = module_sp;
m_data.SetData(DataBufferSP(new DataBufferHeap(bytes, data_length)));
m_data.SetByteOrder(data.GetByteOrder());
m_data.SetAddressByteSize(data.GetAddressByteSize());
}
}
void DWARFExpression::CopyOpcodeData(const void *data,
lldb::offset_t data_length,
ByteOrder byte_order,
uint8_t addr_byte_size) {
if (data && data_length) {
m_data.SetData(DataBufferSP(new DataBufferHeap(data, data_length)));
m_data.SetByteOrder(byte_order);
m_data.SetAddressByteSize(addr_byte_size);
}
}
void DWARFExpression::CopyOpcodeData(uint64_t const_value,
lldb::offset_t const_value_byte_size,
uint8_t addr_byte_size) {
if (const_value_byte_size) {
m_data.SetData(
DataBufferSP(new DataBufferHeap(&const_value, const_value_byte_size)));
m_data.SetByteOrder(endian::InlHostByteOrder());
m_data.SetAddressByteSize(addr_byte_size);
}
}
void DWARFExpression::SetOpcodeData(lldb::ModuleSP module_sp,
const DataExtractor &data,
lldb::offset_t data_offset,
lldb::offset_t data_length) {
m_module_wp = module_sp;
m_data.SetData(data, data_offset, data_length);
}
void DWARFExpression::DumpLocation(Stream *s, lldb::offset_t offset,
lldb::offset_t length,
lldb::DescriptionLevel level,
ABI *abi) const {
if (!m_data.ValidOffsetForDataOfSize(offset, length))
return;
const lldb::offset_t start_offset = offset;
const lldb::offset_t end_offset = offset + length;
while (m_data.ValidOffset(offset) && offset < end_offset) {
const lldb::offset_t op_offset = offset;
const uint8_t op = m_data.GetU8(&offset);
switch (level) {
default:
break;
case lldb::eDescriptionLevelBrief:
if (op_offset > start_offset)
s->PutChar(' ');
break;
case lldb::eDescriptionLevelFull:
case lldb::eDescriptionLevelVerbose:
if (op_offset > start_offset)
s->EOL();
s->Indent();
if (level == lldb::eDescriptionLevelFull)
break;
// Fall through for verbose and print offset and DW_OP prefix..
s->Printf("0x%8.8" PRIx64 ": %s", op_offset,
op >= DW_OP_APPLE_uninit ? "DW_OP_APPLE_" : "DW_OP_");
break;
}
switch (op) {
case DW_OP_addr:
*s << "DW_OP_addr(" << m_data.GetAddress(&offset) << ") ";
break; // 0x03 1 address
case DW_OP_deref:
*s << "DW_OP_deref";
break; // 0x06
case DW_OP_const1u:
s->Printf("DW_OP_const1u(0x%2.2x)", m_data.GetU8(&offset));
break; // 0x08 1 1-byte constant
case DW_OP_const1s:
s->Printf("DW_OP_const1s(0x%2.2x)", m_data.GetU8(&offset));
break; // 0x09 1 1-byte constant
case DW_OP_const2u:
s->Printf("DW_OP_const2u(0x%4.4x)", m_data.GetU16(&offset));
break; // 0x0a 1 2-byte constant
case DW_OP_const2s:
s->Printf("DW_OP_const2s(0x%4.4x)", m_data.GetU16(&offset));
break; // 0x0b 1 2-byte constant
case DW_OP_const4u:
s->Printf("DW_OP_const4u(0x%8.8x)", m_data.GetU32(&offset));
break; // 0x0c 1 4-byte constant
case DW_OP_const4s:
s->Printf("DW_OP_const4s(0x%8.8x)", m_data.GetU32(&offset));
break; // 0x0d 1 4-byte constant
case DW_OP_const8u:
s->Printf("DW_OP_const8u(0x%16.16" PRIx64 ")", m_data.GetU64(&offset));
break; // 0x0e 1 8-byte constant
case DW_OP_const8s:
s->Printf("DW_OP_const8s(0x%16.16" PRIx64 ")", m_data.GetU64(&offset));
break; // 0x0f 1 8-byte constant
case DW_OP_constu:
s->Printf("DW_OP_constu(0x%" PRIx64 ")", m_data.GetULEB128(&offset));
break; // 0x10 1 ULEB128 constant
case DW_OP_consts:
s->Printf("DW_OP_consts(0x%" PRId64 ")", m_data.GetSLEB128(&offset));
break; // 0x11 1 SLEB128 constant
case DW_OP_dup:
s->PutCString("DW_OP_dup");
break; // 0x12
case DW_OP_drop:
s->PutCString("DW_OP_drop");
break; // 0x13
case DW_OP_over:
s->PutCString("DW_OP_over");
break; // 0x14
case DW_OP_pick:
s->Printf("DW_OP_pick(0x%2.2x)", m_data.GetU8(&offset));
break; // 0x15 1 1-byte stack index
case DW_OP_swap:
s->PutCString("DW_OP_swap");
break; // 0x16
case DW_OP_rot:
s->PutCString("DW_OP_rot");
break; // 0x17
case DW_OP_xderef:
s->PutCString("DW_OP_xderef");
break; // 0x18
case DW_OP_abs:
s->PutCString("DW_OP_abs");
break; // 0x19
case DW_OP_and:
s->PutCString("DW_OP_and");
break; // 0x1a
case DW_OP_div:
s->PutCString("DW_OP_div");
break; // 0x1b
case DW_OP_minus:
s->PutCString("DW_OP_minus");
break; // 0x1c
case DW_OP_mod:
s->PutCString("DW_OP_mod");
break; // 0x1d
case DW_OP_mul:
s->PutCString("DW_OP_mul");
break; // 0x1e
case DW_OP_neg:
s->PutCString("DW_OP_neg");
break; // 0x1f
case DW_OP_not:
s->PutCString("DW_OP_not");
break; // 0x20
case DW_OP_or:
s->PutCString("DW_OP_or");
break; // 0x21
case DW_OP_plus:
s->PutCString("DW_OP_plus");
break; // 0x22
case DW_OP_plus_uconst: // 0x23 1 ULEB128 addend
s->Printf("DW_OP_plus_uconst(0x%" PRIx64 ")",
m_data.GetULEB128(&offset));
break;
case DW_OP_shl:
s->PutCString("DW_OP_shl");
break; // 0x24
case DW_OP_shr:
s->PutCString("DW_OP_shr");
break; // 0x25
case DW_OP_shra:
s->PutCString("DW_OP_shra");
break; // 0x26
case DW_OP_xor:
s->PutCString("DW_OP_xor");
break; // 0x27
case DW_OP_skip:
s->Printf("DW_OP_skip(0x%4.4x)", m_data.GetU16(&offset));
break; // 0x2f 1 signed 2-byte constant
case DW_OP_bra:
s->Printf("DW_OP_bra(0x%4.4x)", m_data.GetU16(&offset));
break; // 0x28 1 signed 2-byte constant
case DW_OP_eq:
s->PutCString("DW_OP_eq");
break; // 0x29
case DW_OP_ge:
s->PutCString("DW_OP_ge");
break; // 0x2a
case DW_OP_gt:
s->PutCString("DW_OP_gt");
break; // 0x2b
case DW_OP_le:
s->PutCString("DW_OP_le");
break; // 0x2c
case DW_OP_lt:
s->PutCString("DW_OP_lt");
break; // 0x2d
case DW_OP_ne:
s->PutCString("DW_OP_ne");
break; // 0x2e
case DW_OP_lit0: // 0x30
case DW_OP_lit1: // 0x31
case DW_OP_lit2: // 0x32
case DW_OP_lit3: // 0x33
case DW_OP_lit4: // 0x34
case DW_OP_lit5: // 0x35
case DW_OP_lit6: // 0x36
case DW_OP_lit7: // 0x37
case DW_OP_lit8: // 0x38
case DW_OP_lit9: // 0x39
case DW_OP_lit10: // 0x3A
case DW_OP_lit11: // 0x3B
case DW_OP_lit12: // 0x3C
case DW_OP_lit13: // 0x3D
case DW_OP_lit14: // 0x3E
case DW_OP_lit15: // 0x3F
case DW_OP_lit16: // 0x40
case DW_OP_lit17: // 0x41
case DW_OP_lit18: // 0x42
case DW_OP_lit19: // 0x43
case DW_OP_lit20: // 0x44
case DW_OP_lit21: // 0x45
case DW_OP_lit22: // 0x46
case DW_OP_lit23: // 0x47
case DW_OP_lit24: // 0x48
case DW_OP_lit25: // 0x49
case DW_OP_lit26: // 0x4A
case DW_OP_lit27: // 0x4B
case DW_OP_lit28: // 0x4C
case DW_OP_lit29: // 0x4D
case DW_OP_lit30: // 0x4E
case DW_OP_lit31:
s->Printf("DW_OP_lit%i", op - DW_OP_lit0);
break; // 0x4f
case DW_OP_reg0: // 0x50
case DW_OP_reg1: // 0x51
case DW_OP_reg2: // 0x52
case DW_OP_reg3: // 0x53
case DW_OP_reg4: // 0x54
case DW_OP_reg5: // 0x55
case DW_OP_reg6: // 0x56
case DW_OP_reg7: // 0x57
case DW_OP_reg8: // 0x58
case DW_OP_reg9: // 0x59
case DW_OP_reg10: // 0x5A
case DW_OP_reg11: // 0x5B
case DW_OP_reg12: // 0x5C
case DW_OP_reg13: // 0x5D
case DW_OP_reg14: // 0x5E
case DW_OP_reg15: // 0x5F
case DW_OP_reg16: // 0x60
case DW_OP_reg17: // 0x61
case DW_OP_reg18: // 0x62
case DW_OP_reg19: // 0x63
case DW_OP_reg20: // 0x64
case DW_OP_reg21: // 0x65
case DW_OP_reg22: // 0x66
case DW_OP_reg23: // 0x67
case DW_OP_reg24: // 0x68
case DW_OP_reg25: // 0x69
case DW_OP_reg26: // 0x6A
case DW_OP_reg27: // 0x6B
case DW_OP_reg28: // 0x6C
case DW_OP_reg29: // 0x6D
case DW_OP_reg30: // 0x6E
case DW_OP_reg31: // 0x6F
{
uint32_t reg_num = op - DW_OP_reg0;
if (abi) {
RegisterInfo reg_info;
if (abi->GetRegisterInfoByKind(m_reg_kind, reg_num, reg_info)) {
if (reg_info.name) {
s->PutCString(reg_info.name);
break;
} else if (reg_info.alt_name) {
s->PutCString(reg_info.alt_name);
break;
}
}
}
s->Printf("DW_OP_reg%u", reg_num);
break;
} break;
case DW_OP_breg0:
case DW_OP_breg1:
case DW_OP_breg2:
case DW_OP_breg3:
case DW_OP_breg4:
case DW_OP_breg5:
case DW_OP_breg6:
case DW_OP_breg7:
case DW_OP_breg8:
case DW_OP_breg9:
case DW_OP_breg10:
case DW_OP_breg11:
case DW_OP_breg12:
case DW_OP_breg13:
case DW_OP_breg14:
case DW_OP_breg15:
case DW_OP_breg16:
case DW_OP_breg17:
case DW_OP_breg18:
case DW_OP_breg19:
case DW_OP_breg20:
case DW_OP_breg21:
case DW_OP_breg22:
case DW_OP_breg23:
case DW_OP_breg24:
case DW_OP_breg25:
case DW_OP_breg26:
case DW_OP_breg27:
case DW_OP_breg28:
case DW_OP_breg29:
case DW_OP_breg30:
case DW_OP_breg31: {
uint32_t reg_num = op - DW_OP_breg0;
int64_t reg_offset = m_data.GetSLEB128(&offset);
if (abi) {
RegisterInfo reg_info;
if (abi->GetRegisterInfoByKind(m_reg_kind, reg_num, reg_info)) {
if (reg_info.name) {
s->Printf("[%s%+" PRIi64 "]", reg_info.name, reg_offset);
break;
} else if (reg_info.alt_name) {
s->Printf("[%s%+" PRIi64 "]", reg_info.alt_name, reg_offset);
break;
}
}
}
s->Printf("DW_OP_breg%i(0x%" PRIx64 ")", reg_num, reg_offset);
} break;
case DW_OP_regx: // 0x90 1 ULEB128 register
{
uint32_t reg_num = m_data.GetULEB128(&offset);
if (abi) {
RegisterInfo reg_info;
if (abi->GetRegisterInfoByKind(m_reg_kind, reg_num, reg_info)) {
if (reg_info.name) {
s->PutCString(reg_info.name);
break;
} else if (reg_info.alt_name) {
s->PutCString(reg_info.alt_name);
break;
}
}
}
s->Printf("DW_OP_regx(%" PRIu32 ")", reg_num);
break;
} break;
case DW_OP_fbreg: // 0x91 1 SLEB128 offset
s->Printf("DW_OP_fbreg(%" PRIi64 ")", m_data.GetSLEB128(&offset));
break;
case DW_OP_bregx: // 0x92 2 ULEB128 register followed by SLEB128 offset
{
uint32_t reg_num = m_data.GetULEB128(&offset);
int64_t reg_offset = m_data.GetSLEB128(&offset);
if (abi) {
RegisterInfo reg_info;
if (abi->GetRegisterInfoByKind(m_reg_kind, reg_num, reg_info)) {
if (reg_info.name) {
s->Printf("[%s%+" PRIi64 "]", reg_info.name, reg_offset);
break;
} else if (reg_info.alt_name) {
s->Printf("[%s%+" PRIi64 "]", reg_info.alt_name, reg_offset);
break;
}
}
}
s->Printf("DW_OP_bregx(reg=%" PRIu32 ",offset=%" PRIi64 ")", reg_num,
reg_offset);
} break;
case DW_OP_piece: // 0x93 1 ULEB128 size of piece addressed
s->Printf("DW_OP_piece(0x%" PRIx64 ")", m_data.GetULEB128(&offset));
break;
case DW_OP_deref_size: // 0x94 1 1-byte size of data retrieved
s->Printf("DW_OP_deref_size(0x%2.2x)", m_data.GetU8(&offset));
break;
case DW_OP_xderef_size: // 0x95 1 1-byte size of data retrieved
s->Printf("DW_OP_xderef_size(0x%2.2x)", m_data.GetU8(&offset));
break;
case DW_OP_nop:
s->PutCString("DW_OP_nop");
break; // 0x96
case DW_OP_push_object_address:
s->PutCString("DW_OP_push_object_address");
break; // 0x97 DWARF3
case DW_OP_call2: // 0x98 DWARF3 1 2-byte offset of DIE
s->Printf("DW_OP_call2(0x%4.4x)", m_data.GetU16(&offset));
break;
case DW_OP_call4: // 0x99 DWARF3 1 4-byte offset of DIE
s->Printf("DW_OP_call4(0x%8.8x)", m_data.GetU32(&offset));
break;
case DW_OP_call_ref: // 0x9a DWARF3 1 4- or 8-byte offset of DIE
s->Printf("DW_OP_call_ref(0x%8.8" PRIx64 ")", m_data.GetAddress(&offset));
break;
// case DW_OP_call_frame_cfa: s << "call_frame_cfa"; break;
// // 0x9c DWARF3
// case DW_OP_bit_piece: // 0x9d DWARF3 2
// s->Printf("DW_OP_bit_piece(0x%x, 0x%x)",
// m_data.GetULEB128(&offset), m_data.GetULEB128(&offset));
// break;
// case DW_OP_lo_user: s->PutCString("DW_OP_lo_user"); break;
// // 0xe0
// case DW_OP_hi_user: s->PutCString("DW_OP_hi_user"); break;
// // 0xff
// case DW_OP_APPLE_extern:
// s->Printf("DW_OP_APPLE_extern(%" PRIu64 ")",
// m_data.GetULEB128(&offset));
// break;
// case DW_OP_APPLE_array_ref:
// s->PutCString("DW_OP_APPLE_array_ref");
// break;
case DW_OP_form_tls_address:
s->PutCString("DW_OP_form_tls_address"); // 0x9b
break;
case DW_OP_GNU_addr_index: // 0xfb
s->Printf("DW_OP_GNU_addr_index(0x%" PRIx64 ")",
m_data.GetULEB128(&offset));
break;
case DW_OP_addrx:
s->Printf("DW_OP_addrx(0x%" PRIx64 ")",
m_data.GetULEB128(&offset));
break;
case DW_OP_GNU_const_index: // 0xfc
s->Printf("DW_OP_GNU_const_index(0x%" PRIx64 ")",
m_data.GetULEB128(&offset));
break;
case DW_OP_GNU_push_tls_address:
s->PutCString("DW_OP_GNU_push_tls_address"); // 0xe0
break;
case DW_OP_APPLE_uninit:
s->PutCString("DW_OP_APPLE_uninit"); // 0xF0
break;
// case DW_OP_APPLE_assign: // 0xF1 - pops value off and
// assigns it to second item on stack (2nd item must have
// assignable context)
// s->PutCString("DW_OP_APPLE_assign");
// break;
// case DW_OP_APPLE_address_of: // 0xF2 - gets the address of
// the top stack item (top item must be a variable, or have
// value_type that is an address already)
// s->PutCString("DW_OP_APPLE_address_of");
// break;
// case DW_OP_APPLE_value_of: // 0xF3 - pops the value off the
// stack and pushes the value of that object (top item must be a
// variable, or expression local)
// s->PutCString("DW_OP_APPLE_value_of");
// break;
// case DW_OP_APPLE_deref_type: // 0xF4 - gets the address of
// the top stack item (top item must be a variable, or a clang
// type)
// s->PutCString("DW_OP_APPLE_deref_type");
// break;
// case DW_OP_APPLE_expr_local: // 0xF5 - ULEB128 expression
// local index
// s->Printf("DW_OP_APPLE_expr_local(%" PRIu64 ")",
// m_data.GetULEB128(&offset));
// break;
// case DW_OP_APPLE_constf: // 0xF6 - 1 byte float size,
// followed by constant float data
// {
// uint8_t float_length = m_data.GetU8(&offset);
// s->Printf("DW_OP_APPLE_constf(<%u> ", float_length);
// m_data.Dump(s, offset, eFormatHex, float_length, 1,
// UINT32_MAX, DW_INVALID_ADDRESS, 0, 0);
// s->PutChar(')');
// // Consume the float data
// m_data.GetData(&offset, float_length);
// }
// break;
// case DW_OP_APPLE_scalar_cast:
// s->Printf("DW_OP_APPLE_scalar_cast(%s)",
// Scalar::GetValueTypeAsCString
// ((Scalar::Type)m_data.GetU8(&offset)));
// break;
// case DW_OP_APPLE_clang_cast:
// {
// clang::Type *clang_type = (clang::Type
// *)m_data.GetMaxU64(&offset, sizeof(void*));
// s->Printf("DW_OP_APPLE_clang_cast(%p)", clang_type);
// }
// break;
// case DW_OP_APPLE_clear:
// s->PutCString("DW_OP_APPLE_clear");
// break;
// case DW_OP_APPLE_error: // 0xFF - Stops expression
// evaluation and returns an error (no args)
// s->PutCString("DW_OP_APPLE_error");
// break;
}
}
}
void DWARFExpression::SetLocationListSlide(addr_t slide) {
m_loclist_slide = slide;
}
int DWARFExpression::GetRegisterKind() { return m_reg_kind; }
void DWARFExpression::SetRegisterKind(RegisterKind reg_kind) {
m_reg_kind = reg_kind;
}
bool DWARFExpression::IsLocationList() const {
return m_loclist_slide != LLDB_INVALID_ADDRESS;
}
void DWARFExpression::GetDescription(Stream *s, lldb::DescriptionLevel level,
addr_t location_list_base_addr,
ABI *abi) const {
if (IsLocationList()) {
// We have a location list
lldb::offset_t offset = 0;
uint32_t count = 0;
addr_t curr_base_addr = location_list_base_addr;
while (m_data.ValidOffset(offset)) {
addr_t begin_addr_offset = LLDB_INVALID_ADDRESS;
addr_t end_addr_offset = LLDB_INVALID_ADDRESS;
if (!AddressRangeForLocationListEntry(m_dwarf_cu, m_data, &offset,
begin_addr_offset, end_addr_offset))
break;
if (begin_addr_offset == 0 && end_addr_offset == 0)
break;
if (begin_addr_offset < end_addr_offset) {
if (count > 0)
s->PutCString(", ");
VMRange addr_range(curr_base_addr + begin_addr_offset,
curr_base_addr + end_addr_offset);
addr_range.Dump(s, 0, 8);
s->PutChar('{');
lldb::offset_t location_length = m_data.GetU16(&offset);
DumpLocation(s, offset, location_length, level, abi);
s->PutChar('}');
offset += location_length;
} else {
if ((m_data.GetAddressByteSize() == 4 &&
(begin_addr_offset == UINT32_MAX)) ||
(m_data.GetAddressByteSize() == 8 &&
(begin_addr_offset == UINT64_MAX))) {
curr_base_addr = end_addr_offset + location_list_base_addr;
// We have a new base address
if (count > 0)
s->PutCString(", ");
*s << "base_addr = " << end_addr_offset;
}
}
count++;
}
} else {
// We have a normal location that contains DW_OP location opcodes
DumpLocation(s, 0, m_data.GetByteSize(), level, abi);
}
}
static bool ReadRegisterValueAsScalar(RegisterContext *reg_ctx,
lldb::RegisterKind reg_kind,
uint32_t reg_num, Status *error_ptr,
Value &value) {
if (reg_ctx == NULL) {
if (error_ptr)
error_ptr->SetErrorStringWithFormat("No register context in frame.\n");
} else {
uint32_t native_reg =
reg_ctx->ConvertRegisterKindToRegisterNumber(reg_kind, reg_num);
if (native_reg == LLDB_INVALID_REGNUM) {
if (error_ptr)
error_ptr->SetErrorStringWithFormat("Unable to convert register "
"kind=%u reg_num=%u to a native "
"register number.\n",
reg_kind, reg_num);
} else {
const RegisterInfo *reg_info =
reg_ctx->GetRegisterInfoAtIndex(native_reg);
RegisterValue reg_value;
if (reg_ctx->ReadRegister(reg_info, reg_value)) {
if (reg_value.GetScalarValue(value.GetScalar())) {
value.SetValueType(Value::eValueTypeScalar);
value.SetContext(Value::eContextTypeRegisterInfo,
const_cast<RegisterInfo *>(reg_info));
if (error_ptr)
error_ptr->Clear();
return true;
} else {
// If we get this error, then we need to implement a value buffer in
// the dwarf expression evaluation function...
if (error_ptr)
error_ptr->SetErrorStringWithFormat(
"register %s can't be converted to a scalar value",
reg_info->name);
}
} else {
if (error_ptr)
error_ptr->SetErrorStringWithFormat("register %s is not available",
reg_info->name);
}
}
}
return false;
}
// bool
// DWARFExpression::LocationListContainsLoadAddress (Process* process, const
// Address &addr) const
//{
// return LocationListContainsLoadAddress(process,
// addr.GetLoadAddress(process));
//}
//
// bool
// DWARFExpression::LocationListContainsLoadAddress (Process* process, addr_t
// load_addr) const
//{
// if (load_addr == LLDB_INVALID_ADDRESS)
// return false;
//
// if (IsLocationList())
// {
// lldb::offset_t offset = 0;
//
// addr_t loc_list_base_addr = m_loclist_slide.GetLoadAddress(process);
//
// if (loc_list_base_addr == LLDB_INVALID_ADDRESS)
// return false;
//
// while (m_data.ValidOffset(offset))
// {
// // We need to figure out what the value is for the location.
// addr_t lo_pc = m_data.GetAddress(&offset);
// addr_t hi_pc = m_data.GetAddress(&offset);
// if (lo_pc == 0 && hi_pc == 0)
// break;
// else
// {
// lo_pc += loc_list_base_addr;
// hi_pc += loc_list_base_addr;
//
// if (lo_pc <= load_addr && load_addr < hi_pc)
// return true;
//
// offset += m_data.GetU16(&offset);
// }
// }
// }
// return false;
//}
static offset_t GetOpcodeDataSize(const DataExtractor &data,
const lldb::offset_t data_offset,
const uint8_t op) {
lldb::offset_t offset = data_offset;
switch (op) {
case DW_OP_addr:
case DW_OP_call_ref: // 0x9a 1 address sized offset of DIE (DWARF3)
return data.GetAddressByteSize();
// Opcodes with no arguments
case DW_OP_deref: // 0x06
case DW_OP_dup: // 0x12
case DW_OP_drop: // 0x13
case DW_OP_over: // 0x14
case DW_OP_swap: // 0x16
case DW_OP_rot: // 0x17
case DW_OP_xderef: // 0x18
case DW_OP_abs: // 0x19
case DW_OP_and: // 0x1a
case DW_OP_div: // 0x1b
case DW_OP_minus: // 0x1c
case DW_OP_mod: // 0x1d
case DW_OP_mul: // 0x1e
case DW_OP_neg: // 0x1f
case DW_OP_not: // 0x20
case DW_OP_or: // 0x21
case DW_OP_plus: // 0x22
case DW_OP_shl: // 0x24
case DW_OP_shr: // 0x25
case DW_OP_shra: // 0x26
case DW_OP_xor: // 0x27
case DW_OP_eq: // 0x29
case DW_OP_ge: // 0x2a
case DW_OP_gt: // 0x2b
case DW_OP_le: // 0x2c
case DW_OP_lt: // 0x2d
case DW_OP_ne: // 0x2e
case DW_OP_lit0: // 0x30
case DW_OP_lit1: // 0x31
case DW_OP_lit2: // 0x32
case DW_OP_lit3: // 0x33
case DW_OP_lit4: // 0x34
case DW_OP_lit5: // 0x35
case DW_OP_lit6: // 0x36
case DW_OP_lit7: // 0x37
case DW_OP_lit8: // 0x38
case DW_OP_lit9: // 0x39
case DW_OP_lit10: // 0x3A
case DW_OP_lit11: // 0x3B
case DW_OP_lit12: // 0x3C
case DW_OP_lit13: // 0x3D
case DW_OP_lit14: // 0x3E
case DW_OP_lit15: // 0x3F
case DW_OP_lit16: // 0x40
case DW_OP_lit17: // 0x41
case DW_OP_lit18: // 0x42
case DW_OP_lit19: // 0x43
case DW_OP_lit20: // 0x44
case DW_OP_lit21: // 0x45
case DW_OP_lit22: // 0x46
case DW_OP_lit23: // 0x47
case DW_OP_lit24: // 0x48
case DW_OP_lit25: // 0x49
case DW_OP_lit26: // 0x4A
case DW_OP_lit27: // 0x4B
case DW_OP_lit28: // 0x4C
case DW_OP_lit29: // 0x4D
case DW_OP_lit30: // 0x4E
case DW_OP_lit31: // 0x4f
case DW_OP_reg0: // 0x50
case DW_OP_reg1: // 0x51
case DW_OP_reg2: // 0x52
case DW_OP_reg3: // 0x53
case DW_OP_reg4: // 0x54
case DW_OP_reg5: // 0x55
case DW_OP_reg6: // 0x56
case DW_OP_reg7: // 0x57
case DW_OP_reg8: // 0x58
case DW_OP_reg9: // 0x59
case DW_OP_reg10: // 0x5A
case DW_OP_reg11: // 0x5B
case DW_OP_reg12: // 0x5C
case DW_OP_reg13: // 0x5D
case DW_OP_reg14: // 0x5E
case DW_OP_reg15: // 0x5F
case DW_OP_reg16: // 0x60
case DW_OP_reg17: // 0x61
case DW_OP_reg18: // 0x62
case DW_OP_reg19: // 0x63
case DW_OP_reg20: // 0x64
case DW_OP_reg21: // 0x65
case DW_OP_reg22: // 0x66
case DW_OP_reg23: // 0x67
case DW_OP_reg24: // 0x68
case DW_OP_reg25: // 0x69
case DW_OP_reg26: // 0x6A
case DW_OP_reg27: // 0x6B
case DW_OP_reg28: // 0x6C
case DW_OP_reg29: // 0x6D
case DW_OP_reg30: // 0x6E
case DW_OP_reg31: // 0x6F
case DW_OP_nop: // 0x96
case DW_OP_push_object_address: // 0x97 DWARF3
case DW_OP_form_tls_address: // 0x9b DWARF3
case DW_OP_call_frame_cfa: // 0x9c DWARF3
case DW_OP_stack_value: // 0x9f DWARF4
case DW_OP_GNU_push_tls_address: // 0xe0 GNU extension
return 0;
// Opcodes with a single 1 byte arguments
case DW_OP_const1u: // 0x08 1 1-byte constant
case DW_OP_const1s: // 0x09 1 1-byte constant
case DW_OP_pick: // 0x15 1 1-byte stack index
case DW_OP_deref_size: // 0x94 1 1-byte size of data retrieved
case DW_OP_xderef_size: // 0x95 1 1-byte size of data retrieved
return 1;
// Opcodes with a single 2 byte arguments
case DW_OP_const2u: // 0x0a 1 2-byte constant
case DW_OP_const2s: // 0x0b 1 2-byte constant
case DW_OP_skip: // 0x2f 1 signed 2-byte constant
case DW_OP_bra: // 0x28 1 signed 2-byte constant
case DW_OP_call2: // 0x98 1 2-byte offset of DIE (DWARF3)
return 2;
// Opcodes with a single 4 byte arguments
case DW_OP_const4u: // 0x0c 1 4-byte constant
case DW_OP_const4s: // 0x0d 1 4-byte constant
case DW_OP_call4: // 0x99 1 4-byte offset of DIE (DWARF3)
return 4;
// Opcodes with a single 8 byte arguments
case DW_OP_const8u: // 0x0e 1 8-byte constant
case DW_OP_const8s: // 0x0f 1 8-byte constant
return 8;
// All opcodes that have a single ULEB (signed or unsigned) argument
case DW_OP_addrx: // 0xa1 1 ULEB128 index
case DW_OP_constu: // 0x10 1 ULEB128 constant
case DW_OP_consts: // 0x11 1 SLEB128 constant
case DW_OP_plus_uconst: // 0x23 1 ULEB128 addend
case DW_OP_breg0: // 0x70 1 ULEB128 register
case DW_OP_breg1: // 0x71 1 ULEB128 register
case DW_OP_breg2: // 0x72 1 ULEB128 register
case DW_OP_breg3: // 0x73 1 ULEB128 register
case DW_OP_breg4: // 0x74 1 ULEB128 register
case DW_OP_breg5: // 0x75 1 ULEB128 register
case DW_OP_breg6: // 0x76 1 ULEB128 register
case DW_OP_breg7: // 0x77 1 ULEB128 register
case DW_OP_breg8: // 0x78 1 ULEB128 register
case DW_OP_breg9: // 0x79 1 ULEB128 register
case DW_OP_breg10: // 0x7a 1 ULEB128 register
case DW_OP_breg11: // 0x7b 1 ULEB128 register
case DW_OP_breg12: // 0x7c 1 ULEB128 register
case DW_OP_breg13: // 0x7d 1 ULEB128 register
case DW_OP_breg14: // 0x7e 1 ULEB128 register
case DW_OP_breg15: // 0x7f 1 ULEB128 register
case DW_OP_breg16: // 0x80 1 ULEB128 register
case DW_OP_breg17: // 0x81 1 ULEB128 register
case DW_OP_breg18: // 0x82 1 ULEB128 register
case DW_OP_breg19: // 0x83 1 ULEB128 register
case DW_OP_breg20: // 0x84 1 ULEB128 register
case DW_OP_breg21: // 0x85 1 ULEB128 register
case DW_OP_breg22: // 0x86 1 ULEB128 register
case DW_OP_breg23: // 0x87 1 ULEB128 register
case DW_OP_breg24: // 0x88 1 ULEB128 register
case DW_OP_breg25: // 0x89 1 ULEB128 register
case DW_OP_breg26: // 0x8a 1 ULEB128 register
case DW_OP_breg27: // 0x8b 1 ULEB128 register
case DW_OP_breg28: // 0x8c 1 ULEB128 register
case DW_OP_breg29: // 0x8d 1 ULEB128 register
case DW_OP_breg30: // 0x8e 1 ULEB128 register
case DW_OP_breg31: // 0x8f 1 ULEB128 register
case DW_OP_regx: // 0x90 1 ULEB128 register
case DW_OP_fbreg: // 0x91 1 SLEB128 offset
case DW_OP_piece: // 0x93 1 ULEB128 size of piece addressed
case DW_OP_GNU_addr_index: // 0xfb 1 ULEB128 index
case DW_OP_GNU_const_index: // 0xfc 1 ULEB128 index
data.Skip_LEB128(&offset);
return offset - data_offset;
// All opcodes that have a 2 ULEB (signed or unsigned) arguments
case DW_OP_bregx: // 0x92 2 ULEB128 register followed by SLEB128 offset
case DW_OP_bit_piece: // 0x9d ULEB128 bit size, ULEB128 bit offset (DWARF3);
data.Skip_LEB128(&offset);
data.Skip_LEB128(&offset);
return offset - data_offset;
case DW_OP_implicit_value: // 0x9e ULEB128 size followed by block of that size
// (DWARF4)
{
uint64_t block_len = data.Skip_LEB128(&offset);
offset += block_len;
return offset - data_offset;
}
default:
break;
}
return LLDB_INVALID_OFFSET;
}
lldb::addr_t DWARFExpression::GetLocation_DW_OP_addr(uint32_t op_addr_idx,
bool &error) const {
error = false;
if (IsLocationList())
return LLDB_INVALID_ADDRESS;
lldb::offset_t offset = 0;
uint32_t curr_op_addr_idx = 0;
while (m_data.ValidOffset(offset)) {
const uint8_t op = m_data.GetU8(&offset);
if (op == DW_OP_addr) {
const lldb::addr_t op_file_addr = m_data.GetAddress(&offset);
if (curr_op_addr_idx == op_addr_idx)
return op_file_addr;
else
++curr_op_addr_idx;
} else if (op == DW_OP_GNU_addr_index || op == DW_OP_addrx) {
uint64_t index = m_data.GetULEB128(&offset);
if (curr_op_addr_idx == op_addr_idx) {
if (!m_dwarf_cu) {
error = true;
break;
}
return ReadAddressFromDebugAddrSection(m_dwarf_cu, index);
} else
++curr_op_addr_idx;
} else {
const offset_t op_arg_size = GetOpcodeDataSize(m_data, offset, op);
if (op_arg_size == LLDB_INVALID_OFFSET) {
error = true;
break;
}
offset += op_arg_size;
}
}
return LLDB_INVALID_ADDRESS;
}
bool DWARFExpression::Update_DW_OP_addr(lldb::addr_t file_addr) {
if (IsLocationList())
return false;
lldb::offset_t offset = 0;
while (m_data.ValidOffset(offset)) {
const uint8_t op = m_data.GetU8(&offset);
if (op == DW_OP_addr) {
const uint32_t addr_byte_size = m_data.GetAddressByteSize();
// We have to make a copy of the data as we don't know if this data is
// from a read only memory mapped buffer, so we duplicate all of the data
// first, then modify it, and if all goes well, we then replace the data
// for this expression
// So first we copy the data into a heap buffer
std::unique_ptr<DataBufferHeap> head_data_up(
new DataBufferHeap(m_data.GetDataStart(), m_data.GetByteSize()));
// Make en encoder so we can write the address into the buffer using the
// correct byte order (endianness)
DataEncoder encoder(head_data_up->GetBytes(), head_data_up->GetByteSize(),
m_data.GetByteOrder(), addr_byte_size);
// Replace the address in the new buffer
if (encoder.PutMaxU64(offset, addr_byte_size, file_addr) == UINT32_MAX)
return false;
// All went well, so now we can reset the data using a shared pointer to
// the heap data so "m_data" will now correctly manage the heap data.
m_data.SetData(DataBufferSP(head_data_up.release()));
return true;
} else {
const offset_t op_arg_size = GetOpcodeDataSize(m_data, offset, op);
if (op_arg_size == LLDB_INVALID_OFFSET)
break;
offset += op_arg_size;
}
}
return false;
}
bool DWARFExpression::ContainsThreadLocalStorage() const {
// We are assuming for now that any thread local variable will not have a
// location list. This has been true for all thread local variables we have
// seen so far produced by any compiler.
if (IsLocationList())
return false;
lldb::offset_t offset = 0;
while (m_data.ValidOffset(offset)) {
const uint8_t op = m_data.GetU8(&offset);
if (op == DW_OP_form_tls_address || op == DW_OP_GNU_push_tls_address)
return true;
const offset_t op_arg_size = GetOpcodeDataSize(m_data, offset, op);
if (op_arg_size == LLDB_INVALID_OFFSET)
return false;
else
offset += op_arg_size;
}
return false;
}
bool DWARFExpression::LinkThreadLocalStorage(
lldb::ModuleSP new_module_sp,
std::function<lldb::addr_t(lldb::addr_t file_addr)> const
&link_address_callback) {
// We are assuming for now that any thread local variable will not have a
// location list. This has been true for all thread local variables we have
// seen so far produced by any compiler.
if (IsLocationList())
return false;
const uint32_t addr_byte_size = m_data.GetAddressByteSize();
// We have to make a copy of the data as we don't know if this data is from a
// read only memory mapped buffer, so we duplicate all of the data first,
// then modify it, and if all goes well, we then replace the data for this
// expression
// So first we copy the data into a heap buffer
std::shared_ptr<DataBufferHeap> heap_data_sp(
new DataBufferHeap(m_data.GetDataStart(), m_data.GetByteSize()));
// Make en encoder so we can write the address into the buffer using the
// correct byte order (endianness)
DataEncoder encoder(heap_data_sp->GetBytes(), heap_data_sp->GetByteSize(),
m_data.GetByteOrder(), addr_byte_size);
lldb::offset_t offset = 0;
lldb::offset_t const_offset = 0;
lldb::addr_t const_value = 0;
size_t const_byte_size = 0;
while (m_data.ValidOffset(offset)) {
const uint8_t op = m_data.GetU8(&offset);
bool decoded_data = false;
switch (op) {
case DW_OP_const4u:
// Remember the const offset in case we later have a
// DW_OP_form_tls_address or DW_OP_GNU_push_tls_address
const_offset = offset;
const_value = m_data.GetU32(&offset);
decoded_data = true;
const_byte_size = 4;
break;
case DW_OP_const8u:
// Remember the const offset in case we later have a
// DW_OP_form_tls_address or DW_OP_GNU_push_tls_address
const_offset = offset;
const_value = m_data.GetU64(&offset);
decoded_data = true;
const_byte_size = 8;
break;
case DW_OP_form_tls_address:
case DW_OP_GNU_push_tls_address:
// DW_OP_form_tls_address and DW_OP_GNU_push_tls_address must be preceded
// by a file address on the stack. We assume that DW_OP_const4u or
// DW_OP_const8u is used for these values, and we check that the last
// opcode we got before either of these was DW_OP_const4u or
// DW_OP_const8u. If so, then we can link the value accodingly. For
// Darwin, the value in the DW_OP_const4u or DW_OP_const8u is the file
// address of a structure that contains a function pointer, the pthread
// key and the offset into the data pointed to by the pthread key. So we
// must link this address and also set the module of this expression to
// the new_module_sp so we can resolve the file address correctly
if (const_byte_size > 0) {
lldb::addr_t linked_file_addr = link_address_callback(const_value);
if (linked_file_addr == LLDB_INVALID_ADDRESS)
return false;
// Replace the address in the new buffer
if (encoder.PutMaxU64(const_offset, const_byte_size,
linked_file_addr) == UINT32_MAX)
return false;
}
break;
default:
const_offset = 0;
const_value = 0;
const_byte_size = 0;
break;
}
if (!decoded_data) {
const offset_t op_arg_size = GetOpcodeDataSize(m_data, offset, op);
if (op_arg_size == LLDB_INVALID_OFFSET)
return false;
else
offset += op_arg_size;
}
}
// If we linked the TLS address correctly, update the module so that when the
// expression is evaluated it can resolve the file address to a load address
// and read the
// TLS data
m_module_wp = new_module_sp;
m_data.SetData(heap_data_sp);
return true;
}
bool DWARFExpression::LocationListContainsAddress(
lldb::addr_t loclist_base_addr, lldb::addr_t addr) const {
if (addr == LLDB_INVALID_ADDRESS)
return false;
if (IsLocationList()) {
lldb::offset_t offset = 0;
if (loclist_base_addr == LLDB_INVALID_ADDRESS)
return false;
while (m_data.ValidOffset(offset)) {
// We need to figure out what the value is for the location.
addr_t lo_pc = LLDB_INVALID_ADDRESS;
addr_t hi_pc = LLDB_INVALID_ADDRESS;
if (!AddressRangeForLocationListEntry(m_dwarf_cu, m_data, &offset, lo_pc,
hi_pc))
break;
if (lo_pc == 0 && hi_pc == 0)
break;
lo_pc += loclist_base_addr - m_loclist_slide;
hi_pc += loclist_base_addr - m_loclist_slide;
if (lo_pc <= addr && addr < hi_pc)
return true;
offset += m_data.GetU16(&offset);
}
}
return false;
}
bool DWARFExpression::GetLocation(addr_t base_addr, addr_t pc,
lldb::offset_t &offset,
lldb::offset_t &length) {
offset = 0;
if (!IsLocationList()) {
length = m_data.GetByteSize();
return true;
}
if (base_addr != LLDB_INVALID_ADDRESS && pc != LLDB_INVALID_ADDRESS) {
addr_t curr_base_addr = base_addr;
while (m_data.ValidOffset(offset)) {
// We need to figure out what the value is for the location.
addr_t lo_pc = LLDB_INVALID_ADDRESS;
addr_t hi_pc = LLDB_INVALID_ADDRESS;
if (!AddressRangeForLocationListEntry(m_dwarf_cu, m_data, &offset, lo_pc,
hi_pc))
break;
if (lo_pc == 0 && hi_pc == 0)
break;
lo_pc += curr_base_addr - m_loclist_slide;
hi_pc += curr_base_addr - m_loclist_slide;
length = m_data.GetU16(&offset);
if (length > 0 && lo_pc <= pc && pc < hi_pc)
return true;
offset += length;
}
}
offset = LLDB_INVALID_OFFSET;
length = 0;
return false;
}
bool DWARFExpression::DumpLocationForAddress(Stream *s,
lldb::DescriptionLevel level,
addr_t base_addr, addr_t address,
ABI *abi) {
lldb::offset_t offset = 0;
lldb::offset_t length = 0;
if (GetLocation(base_addr, address, offset, length)) {
if (length > 0) {
DumpLocation(s, offset, length, level, abi);
return true;
}
}
return false;
}
bool DWARFExpression::Evaluate(ExecutionContextScope *exe_scope,
lldb::addr_t loclist_base_load_addr,
const Value *initial_value_ptr,
const Value *object_address_ptr, Value &result,
Status *error_ptr) const {
ExecutionContext exe_ctx(exe_scope);
return Evaluate(&exe_ctx, nullptr, loclist_base_load_addr, initial_value_ptr,
object_address_ptr, result, error_ptr);
}
bool DWARFExpression::Evaluate(ExecutionContext *exe_ctx,
RegisterContext *reg_ctx,
lldb::addr_t loclist_base_load_addr,
const Value *initial_value_ptr,
const Value *object_address_ptr, Value &result,
Status *error_ptr) const {
ModuleSP module_sp = m_module_wp.lock();
if (IsLocationList()) {
lldb::offset_t offset = 0;
addr_t pc;
StackFrame *frame = NULL;
if (reg_ctx)
pc = reg_ctx->GetPC();
else {
frame = exe_ctx->GetFramePtr();
if (!frame)
return false;
RegisterContextSP reg_ctx_sp = frame->GetRegisterContext();
if (!reg_ctx_sp)
return false;
pc = reg_ctx_sp->GetPC();
}
if (loclist_base_load_addr != LLDB_INVALID_ADDRESS) {
if (pc == LLDB_INVALID_ADDRESS) {
if (error_ptr)
error_ptr->SetErrorString("Invalid PC in frame.");
return false;
}
addr_t curr_loclist_base_load_addr = loclist_base_load_addr;
while (m_data.ValidOffset(offset)) {
// We need to figure out what the value is for the location.
addr_t lo_pc = LLDB_INVALID_ADDRESS;
addr_t hi_pc = LLDB_INVALID_ADDRESS;
if (!AddressRangeForLocationListEntry(m_dwarf_cu, m_data, &offset,
lo_pc, hi_pc))
break;
if (lo_pc == 0 && hi_pc == 0)
break;
lo_pc += curr_loclist_base_load_addr - m_loclist_slide;
hi_pc += curr_loclist_base_load_addr - m_loclist_slide;
uint16_t length = m_data.GetU16(&offset);
if (length > 0 && lo_pc <= pc && pc < hi_pc) {
return DWARFExpression::Evaluate(
exe_ctx, reg_ctx, module_sp, m_data, m_dwarf_cu, offset, length,
m_reg_kind, initial_value_ptr, object_address_ptr, result,
error_ptr);
}
offset += length;
}
}
if (error_ptr)
error_ptr->SetErrorString("variable not available");
return false;
}
// Not a location list, just a single expression.
return DWARFExpression::Evaluate(
exe_ctx, reg_ctx, module_sp, m_data, m_dwarf_cu, 0, m_data.GetByteSize(),
m_reg_kind, initial_value_ptr, object_address_ptr, result, error_ptr);
}
bool DWARFExpression::Evaluate(
ExecutionContext *exe_ctx, RegisterContext *reg_ctx,
lldb::ModuleSP module_sp, const DataExtractor &opcodes,
DWARFUnit *dwarf_cu, const lldb::offset_t opcodes_offset,
const lldb::offset_t opcodes_length, const lldb::RegisterKind reg_kind,
const Value *initial_value_ptr, const Value *object_address_ptr,
Value &result, Status *error_ptr) {
if (opcodes_length == 0) {
if (error_ptr)
error_ptr->SetErrorString(
"no location, value may have been optimized out");
return false;
}
std::vector<Value> stack;
Process *process = NULL;
StackFrame *frame = NULL;
if (exe_ctx) {
process = exe_ctx->GetProcessPtr();
frame = exe_ctx->GetFramePtr();
}
if (reg_ctx == NULL && frame)
reg_ctx = frame->GetRegisterContext().get();
if (initial_value_ptr)
stack.push_back(*initial_value_ptr);
lldb::offset_t offset = opcodes_offset;
const lldb::offset_t end_offset = opcodes_offset + opcodes_length;
Value tmp;
uint32_t reg_num;
/// Insertion point for evaluating multi-piece expression.
uint64_t op_piece_offset = 0;
Value pieces; // Used for DW_OP_piece
// Make sure all of the data is available in opcodes.
if (!opcodes.ValidOffsetForDataOfSize(opcodes_offset, opcodes_length)) {
if (error_ptr)
error_ptr->SetErrorString(
"invalid offset and/or length for opcodes buffer.");
return false;
}
Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_EXPRESSIONS));
while (opcodes.ValidOffset(offset) && offset < end_offset) {
const lldb::offset_t op_offset = offset;
const uint8_t op = opcodes.GetU8(&offset);
if (log && log->GetVerbose()) {
size_t count = stack.size();
log->Printf("Stack before operation has %" PRIu64 " values:",
(uint64_t)count);
for (size_t i = 0; i < count; ++i) {
StreamString new_value;
new_value.Printf("[%" PRIu64 "]", (uint64_t)i);
stack[i].Dump(&new_value);
log->Printf(" %s", new_value.GetData());
}
log->Printf("0x%8.8" PRIx64 ": %s", op_offset, DW_OP_value_to_name(op));
}
switch (op) {
// The DW_OP_addr operation has a single operand that encodes a machine
// address and whose size is the size of an address on the target machine.
case DW_OP_addr:
stack.push_back(Scalar(opcodes.GetAddress(&offset)));
stack.back().SetValueType(Value::eValueTypeFileAddress);
// Convert the file address to a load address, so subsequent
// DWARF operators can operate on it.
if (frame)
stack.back().ConvertToLoadAddress(module_sp.get(),
frame->CalculateTarget().get());
break;
// The DW_OP_addr_sect_offset4 is used for any location expressions in
// shared libraries that have a location like:
// DW_OP_addr(0x1000)
// If this address resides in a shared library, then this virtual address
// won't make sense when it is evaluated in the context of a running
// process where shared libraries have been slid. To account for this, this
// new address type where we can store the section pointer and a 4 byte
// offset.
// case DW_OP_addr_sect_offset4:
// {
// result_type = eResultTypeFileAddress;
// lldb::Section *sect = (lldb::Section
// *)opcodes.GetMaxU64(&offset, sizeof(void *));
// lldb::addr_t sect_offset = opcodes.GetU32(&offset);
//
// Address so_addr (sect, sect_offset);
// lldb::addr_t load_addr = so_addr.GetLoadAddress();
// if (load_addr != LLDB_INVALID_ADDRESS)
// {
// // We successfully resolve a file address to a load
// // address.
// stack.push_back(load_addr);
// break;
// }
// else
// {
// // We were able
// if (error_ptr)
// error_ptr->SetErrorStringWithFormat ("Section %s in
// %s is not currently loaded.\n",
// sect->GetName().AsCString(),
// sect->GetModule()->GetFileSpec().GetFilename().AsCString());
// return false;
// }
// }
// break;
// OPCODE: DW_OP_deref
// OPERANDS: none
// DESCRIPTION: Pops the top stack entry and treats it as an address.
// The value retrieved from that address is pushed. The size of the data
// retrieved from the dereferenced address is the size of an address on the
// target machine.
case DW_OP_deref: {
if (stack.empty()) {
if (error_ptr)
error_ptr->SetErrorString("Expression stack empty for DW_OP_deref.");
return false;
}
Value::ValueType value_type = stack.back().GetValueType();
switch (value_type) {
case Value::eValueTypeHostAddress: {
void *src = (void *)stack.back().GetScalar().ULongLong();
intptr_t ptr;
::memcpy(&ptr, src, sizeof(void *));
stack.back().GetScalar() = ptr;
stack.back().ClearContext();
} break;
case Value::eValueTypeFileAddress: {
auto file_addr = stack.back().GetScalar().ULongLong(
LLDB_INVALID_ADDRESS);
if (!module_sp) {
if (error_ptr)
error_ptr->SetErrorStringWithFormat(
"need module to resolve file address for DW_OP_deref");
return false;
}
Address so_addr;
if (!module_sp->ResolveFileAddress(file_addr, so_addr)) {
if (error_ptr)
error_ptr->SetErrorStringWithFormat(
"failed to resolve file address in module");
return false;
}
addr_t load_Addr = so_addr.GetLoadAddress(exe_ctx->GetTargetPtr());
if (load_Addr == LLDB_INVALID_ADDRESS) {
if (error_ptr)
error_ptr->SetErrorStringWithFormat(
"failed to resolve load address");
return false;
}
stack.back().GetScalar() = load_Addr;
stack.back().SetValueType(Value::eValueTypeLoadAddress);
// Fall through to load address code below...
} LLVM_FALLTHROUGH;
case Value::eValueTypeLoadAddress:
if (exe_ctx) {
if (process) {
lldb::addr_t pointer_addr =
stack.back().GetScalar().ULongLong(LLDB_INVALID_ADDRESS);
Status error;
lldb::addr_t pointer_value =
process->ReadPointerFromMemory(pointer_addr, error);
if (pointer_value != LLDB_INVALID_ADDRESS) {
stack.back().GetScalar() = pointer_value;
stack.back().ClearContext();
} else {
if (error_ptr)
error_ptr->SetErrorStringWithFormat(
"Failed to dereference pointer from 0x%" PRIx64
" for DW_OP_deref: %s\n",
pointer_addr, error.AsCString());
return false;
}
} else {
if (error_ptr)
error_ptr->SetErrorStringWithFormat(
"NULL process for DW_OP_deref.\n");
return false;
}
} else {
if (error_ptr)
error_ptr->SetErrorStringWithFormat(
"NULL execution context for DW_OP_deref.\n");
return false;
}
break;
default:
break;
}
} break;
// OPCODE: DW_OP_deref_size
// OPERANDS: 1
// 1 - uint8_t that specifies the size of the data to dereference.
// DESCRIPTION: Behaves like the DW_OP_deref operation: it pops the top
// stack entry and treats it as an address. The value retrieved from that
// address is pushed. In the DW_OP_deref_size operation, however, the size
// in bytes of the data retrieved from the dereferenced address is
// specified by the single operand. This operand is a 1-byte unsigned
// integral constant whose value may not be larger than the size of an
// address on the target machine. The data retrieved is zero extended to
// the size of an address on the target machine before being pushed on the
// expression stack.
case DW_OP_deref_size: {
if (stack.empty()) {
if (error_ptr)
error_ptr->SetErrorString(
"Expression stack empty for DW_OP_deref_size.");
return false;
}
uint8_t size = opcodes.GetU8(&offset);
Value::ValueType value_type = stack.back().GetValueType();
switch (value_type) {
case Value::eValueTypeHostAddress: {
void *src = (void *)stack.back().GetScalar().ULongLong();
intptr_t ptr;
::memcpy(&ptr, src, sizeof(void *));
// I can't decide whether the size operand should apply to the bytes in
// their
// lldb-host endianness or the target endianness.. I doubt this'll ever
// come up but I'll opt for assuming big endian regardless.
switch (size) {
case 1:
ptr = ptr & 0xff;
break;
case 2:
ptr = ptr & 0xffff;
break;
case 3:
ptr = ptr & 0xffffff;
break;
case 4:
ptr = ptr & 0xffffffff;
break;
// the casts are added to work around the case where intptr_t is a 32
// bit quantity;
// presumably we won't hit the 5..7 cases if (void*) is 32-bits in this
// program.
case 5:
ptr = (intptr_t)ptr & 0xffffffffffULL;
break;
case 6:
ptr = (intptr_t)ptr & 0xffffffffffffULL;
break;
case 7:
ptr = (intptr_t)ptr & 0xffffffffffffffULL;
break;
default:
break;
}
stack.back().GetScalar() = ptr;
stack.back().ClearContext();
} break;
case Value::eValueTypeLoadAddress:
if (exe_ctx) {
if (process) {
lldb::addr_t pointer_addr =
stack.back().GetScalar().ULongLong(LLDB_INVALID_ADDRESS);
uint8_t addr_bytes[sizeof(lldb::addr_t)];
Status error;
if (process->ReadMemory(pointer_addr, &addr_bytes, size, error) ==
size) {
DataExtractor addr_data(addr_bytes, sizeof(addr_bytes),
process->GetByteOrder(), size);
lldb::offset_t addr_data_offset = 0;
switch (size) {
case 1:
stack.back().GetScalar() = addr_data.GetU8(&addr_data_offset);
break;
case 2:
stack.back().GetScalar() = addr_data.GetU16(&addr_data_offset);
break;
case 4:
stack.back().GetScalar() = addr_data.GetU32(&addr_data_offset);
break;
case 8:
stack.back().GetScalar() = addr_data.GetU64(&addr_data_offset);
break;
default:
stack.back().GetScalar() =
addr_data.GetPointer(&addr_data_offset);
}
stack.back().ClearContext();
} else {
if (error_ptr)
error_ptr->SetErrorStringWithFormat(
"Failed to dereference pointer from 0x%" PRIx64
" for DW_OP_deref: %s\n",
pointer_addr, error.AsCString());
return false;
}
} else {
if (error_ptr)
error_ptr->SetErrorStringWithFormat(
"NULL process for DW_OP_deref.\n");
return false;
}
} else {
if (error_ptr)
error_ptr->SetErrorStringWithFormat(
"NULL execution context for DW_OP_deref.\n");
return false;
}
break;
default:
break;
}
} break;
// OPCODE: DW_OP_xderef_size
// OPERANDS: 1
// 1 - uint8_t that specifies the size of the data to dereference.
// DESCRIPTION: Behaves like the DW_OP_xderef operation: the entry at
// the top of the stack is treated as an address. The second stack entry is
// treated as an "address space identifier" for those architectures that
// support multiple address spaces. The top two stack elements are popped,
// a data item is retrieved through an implementation-defined address
// calculation and pushed as the new stack top. In the DW_OP_xderef_size
// operation, however, the size in bytes of the data retrieved from the
// dereferenced address is specified by the single operand. This operand is
// a 1-byte unsigned integral constant whose value may not be larger than
// the size of an address on the target machine. The data retrieved is zero
// extended to the size of an address on the target machine before being
// pushed on the expression stack.
case DW_OP_xderef_size:
if (error_ptr)
error_ptr->SetErrorString("Unimplemented opcode: DW_OP_xderef_size.");
return false;
// OPCODE: DW_OP_xderef
// OPERANDS: none
// DESCRIPTION: Provides an extended dereference mechanism. The entry at
// the top of the stack is treated as an address. The second stack entry is
// treated as an "address space identifier" for those architectures that
// support multiple address spaces. The top two stack elements are popped,
// a data item is retrieved through an implementation-defined address
// calculation and pushed as the new stack top. The size of the data
// retrieved from the dereferenced address is the size of an address on the
// target machine.
case DW_OP_xderef:
if (error_ptr)
error_ptr->SetErrorString("Unimplemented opcode: DW_OP_xderef.");
return false;
// All DW_OP_constXXX opcodes have a single operand as noted below:
//
// Opcode Operand 1
// DW_OP_const1u 1-byte unsigned integer constant DW_OP_const1s
// 1-byte signed integer constant DW_OP_const2u 2-byte unsigned integer
// constant DW_OP_const2s 2-byte signed integer constant DW_OP_const4u
// 4-byte unsigned integer constant DW_OP_const4s 4-byte signed integer
// constant DW_OP_const8u 8-byte unsigned integer constant DW_OP_const8s
// 8-byte signed integer constant DW_OP_constu unsigned LEB128 integer
// constant DW_OP_consts signed LEB128 integer constant
case DW_OP_const1u:
stack.push_back(Scalar((uint8_t)opcodes.GetU8(&offset)));
break;
case DW_OP_const1s:
stack.push_back(Scalar((int8_t)opcodes.GetU8(&offset)));
break;
case DW_OP_const2u:
stack.push_back(Scalar((uint16_t)opcodes.GetU16(&offset)));
break;
case DW_OP_const2s:
stack.push_back(Scalar((int16_t)opcodes.GetU16(&offset)));
break;
case DW_OP_const4u:
stack.push_back(Scalar((uint32_t)opcodes.GetU32(&offset)));
break;
case DW_OP_const4s:
stack.push_back(Scalar((int32_t)opcodes.GetU32(&offset)));
break;
case DW_OP_const8u:
stack.push_back(Scalar((uint64_t)opcodes.GetU64(&offset)));
break;
case DW_OP_const8s:
stack.push_back(Scalar((int64_t)opcodes.GetU64(&offset)));
break;
case DW_OP_constu:
stack.push_back(Scalar(opcodes.GetULEB128(&offset)));
break;
case DW_OP_consts:
stack.push_back(Scalar(opcodes.GetSLEB128(&offset)));
break;
// OPCODE: DW_OP_dup
// OPERANDS: none
// DESCRIPTION: duplicates the value at the top of the stack
case DW_OP_dup:
if (stack.empty()) {
if (error_ptr)
error_ptr->SetErrorString("Expression stack empty for DW_OP_dup.");
return false;
} else
stack.push_back(stack.back());
break;
// OPCODE: DW_OP_drop
// OPERANDS: none
// DESCRIPTION: pops the value at the top of the stack
case DW_OP_drop:
if (stack.empty()) {
if (error_ptr)
error_ptr->SetErrorString("Expression stack empty for DW_OP_drop.");
return false;
} else
stack.pop_back();
break;
// OPCODE: DW_OP_over
// OPERANDS: none
// DESCRIPTION: Duplicates the entry currently second in the stack at
// the top of the stack.
case DW_OP_over:
if (stack.size() < 2) {
if (error_ptr)
error_ptr->SetErrorString(
"Expression stack needs at least 2 items for DW_OP_over.");
return false;
} else
stack.push_back(stack[stack.size() - 2]);
break;
// OPCODE: DW_OP_pick
// OPERANDS: uint8_t index into the current stack
// DESCRIPTION: The stack entry with the specified index (0 through 255,
// inclusive) is pushed on the stack
case DW_OP_pick: {
uint8_t pick_idx = opcodes.GetU8(&offset);
if (pick_idx < stack.size())
stack.push_back(stack[stack.size() - 1 - pick_idx]);
else {
if (error_ptr)
error_ptr->SetErrorStringWithFormat(
"Index %u out of range for DW_OP_pick.\n", pick_idx);
return false;
}
} break;
// OPCODE: DW_OP_swap
// OPERANDS: none
// DESCRIPTION: swaps the top two stack entries. The entry at the top
// of the stack becomes the second stack entry, and the second entry
// becomes the top of the stack
case DW_OP_swap:
if (stack.size() < 2) {
if (error_ptr)
error_ptr->SetErrorString(
"Expression stack needs at least 2 items for DW_OP_swap.");
return false;
} else {
tmp = stack.back();
stack.back() = stack[stack.size() - 2];
stack[stack.size() - 2] = tmp;
}
break;
// OPCODE: DW_OP_rot
// OPERANDS: none
// DESCRIPTION: Rotates the first three stack entries. The entry at
// the top of the stack becomes the third stack entry, the second entry
// becomes the top of the stack, and the third entry becomes the second
// entry.
case DW_OP_rot:
if (stack.size() < 3) {
if (error_ptr)
error_ptr->SetErrorString(
"Expression stack needs at least 3 items for DW_OP_rot.");
return false;
} else {
size_t last_idx = stack.size() - 1;
Value old_top = stack[last_idx];
stack[last_idx] = stack[last_idx - 1];
stack[last_idx - 1] = stack[last_idx - 2];
stack[last_idx - 2] = old_top;
}
break;
// OPCODE: DW_OP_abs
// OPERANDS: none
// DESCRIPTION: pops the top stack entry, interprets it as a signed
// value and pushes its absolute value. If the absolute value can not be
// represented, the result is undefined.
case DW_OP_abs:
if (stack.empty()) {
if (error_ptr)
error_ptr->SetErrorString(
"Expression stack needs at least 1 item for DW_OP_abs.");
return false;
} else if (!stack.back().ResolveValue(exe_ctx).AbsoluteValue()) {
if (error_ptr)
error_ptr->SetErrorString(
"Failed to take the absolute value of the first stack item.");
return false;
}
break;
// OPCODE: DW_OP_and
// OPERANDS: none
// DESCRIPTION: pops the top two stack values, performs a bitwise and
// operation on the two, and pushes the result.
case DW_OP_and:
if (stack.size() < 2) {
if (error_ptr)
error_ptr->SetErrorString(
"Expression stack needs at least 2 items for DW_OP_and.");
return false;
} else {
tmp = stack.back();
stack.pop_back();
stack.back().ResolveValue(exe_ctx) =
stack.back().ResolveValue(exe_ctx) & tmp.ResolveValue(exe_ctx);
}
break;
// OPCODE: DW_OP_div
// OPERANDS: none
// DESCRIPTION: pops the top two stack values, divides the former second
// entry by the former top of the stack using signed division, and pushes
// the result.
case DW_OP_div:
if (stack.size() < 2) {
if (error_ptr)
error_ptr->SetErrorString(
"Expression stack needs at least 2 items for DW_OP_div.");
return false;
} else {
tmp = stack.back();
if (tmp.ResolveValue(exe_ctx).IsZero()) {
if (error_ptr)
error_ptr->SetErrorString("Divide by zero.");
return false;
} else {
stack.pop_back();
stack.back() =
stack.back().ResolveValue(exe_ctx) / tmp.ResolveValue(exe_ctx);
if (!stack.back().ResolveValue(exe_ctx).IsValid()) {
if (error_ptr)
error_ptr->SetErrorString("Divide failed.");
return false;
}
}
}
break;
// OPCODE: DW_OP_minus
// OPERANDS: none
// DESCRIPTION: pops the top two stack values, subtracts the former top
// of the stack from the former second entry, and pushes the result.
case DW_OP_minus:
if (stack.size() < 2) {
if (error_ptr)
error_ptr->SetErrorString(
"Expression stack needs at least 2 items for DW_OP_minus.");
return false;
} else {
tmp = stack.back();
stack.pop_back();
stack.back().ResolveValue(exe_ctx) =
stack.back().ResolveValue(exe_ctx) - tmp.ResolveValue(exe_ctx);
}
break;
// OPCODE: DW_OP_mod
// OPERANDS: none
// DESCRIPTION: pops the top two stack values and pushes the result of
// the calculation: former second stack entry modulo the former top of the
// stack.
case DW_OP_mod:
if (stack.size() < 2) {
if (error_ptr)
error_ptr->SetErrorString(
"Expression stack needs at least 2 items for DW_OP_mod.");
return false;
} else {
tmp = stack.back();
stack.pop_back();
stack.back().ResolveValue(exe_ctx) =
stack.back().ResolveValue(exe_ctx) % tmp.ResolveValue(exe_ctx);
}
break;
// OPCODE: DW_OP_mul
// OPERANDS: none
// DESCRIPTION: pops the top two stack entries, multiplies them
// together, and pushes the result.
case DW_OP_mul:
if (stack.size() < 2) {
if (error_ptr)
error_ptr->SetErrorString(
"Expression stack needs at least 2 items for DW_OP_mul.");
return false;
} else {
tmp = stack.back();
stack.pop_back();
stack.back().ResolveValue(exe_ctx) =
stack.back().ResolveValue(exe_ctx) * tmp.ResolveValue(exe_ctx);
}
break;
// OPCODE: DW_OP_neg
// OPERANDS: none
// DESCRIPTION: pops the top stack entry, and pushes its negation.
case DW_OP_neg:
if (stack.empty()) {
if (error_ptr)
error_ptr->SetErrorString(
"Expression stack needs at least 1 item for DW_OP_neg.");
return false;
} else {
if (!stack.back().ResolveValue(exe_ctx).UnaryNegate()) {
if (error_ptr)
error_ptr->SetErrorString("Unary negate failed.");
return false;
}
}
break;
// OPCODE: DW_OP_not
// OPERANDS: none
// DESCRIPTION: pops the top stack entry, and pushes its bitwise
// complement
case DW_OP_not:
if (stack.empty()) {
if (error_ptr)
error_ptr->SetErrorString(
"Expression stack needs at least 1 item for DW_OP_not.");
return false;
} else {
if (!stack.back().ResolveValue(exe_ctx).OnesComplement()) {
if (error_ptr)
error_ptr->SetErrorString("Logical NOT failed.");
return false;
}
}
break;
// OPCODE: DW_OP_or
// OPERANDS: none
// DESCRIPTION: pops the top two stack entries, performs a bitwise or
// operation on the two, and pushes the result.
case DW_OP_or:
if (stack.size() < 2) {
if (error_ptr)
error_ptr->SetErrorString(
"Expression stack needs at least 2 items for DW_OP_or.");
return false;
} else {
tmp = stack.back();
stack.pop_back();
stack.back().ResolveValue(exe_ctx) =
stack.back().ResolveValue(exe_ctx) | tmp.ResolveValue(exe_ctx);
}
break;
// OPCODE: DW_OP_plus
// OPERANDS: none
// DESCRIPTION: pops the top two stack entries, adds them together, and
// pushes the result.
case DW_OP_plus:
if (stack.size() < 2) {
if (error_ptr)
error_ptr->SetErrorString(
"Expression stack needs at least 2 items for DW_OP_plus.");
return false;
} else {
tmp = stack.back();
stack.pop_back();
stack.back().GetScalar() += tmp.GetScalar();
}
break;
// OPCODE: DW_OP_plus_uconst
// OPERANDS: none
// DESCRIPTION: pops the top stack entry, adds it to the unsigned LEB128
// constant operand and pushes the result.
case DW_OP_plus_uconst:
if (stack.empty()) {
if (error_ptr)
error_ptr->SetErrorString(
"Expression stack needs at least 1 item for DW_OP_plus_uconst.");
return false;
} else {
const uint64_t uconst_value = opcodes.GetULEB128(&offset);
// Implicit conversion from a UINT to a Scalar...
stack.back().GetScalar() += uconst_value;
if (!stack.back().GetScalar().IsValid()) {
if (error_ptr)
error_ptr->SetErrorString("DW_OP_plus_uconst failed.");
return false;
}
}
break;
// OPCODE: DW_OP_shl
// OPERANDS: none
// DESCRIPTION: pops the top two stack entries, shifts the former
// second entry left by the number of bits specified by the former top of
// the stack, and pushes the result.
case DW_OP_shl:
if (stack.size() < 2) {
if (error_ptr)
error_ptr->SetErrorString(
"Expression stack needs at least 2 items for DW_OP_shl.");
return false;
} else {
tmp = stack.back();
stack.pop_back();
stack.back().ResolveValue(exe_ctx) <<= tmp.ResolveValue(exe_ctx);
}
break;
// OPCODE: DW_OP_shr
// OPERANDS: none
// DESCRIPTION: pops the top two stack entries, shifts the former second
// entry right logically (filling with zero bits) by the number of bits
// specified by the former top of the stack, and pushes the result.
case DW_OP_shr:
if (stack.size() < 2) {
if (error_ptr)
error_ptr->SetErrorString(
"Expression stack needs at least 2 items for DW_OP_shr.");
return false;
} else {
tmp = stack.back();
stack.pop_back();
if (!stack.back().ResolveValue(exe_ctx).ShiftRightLogical(
tmp.ResolveValue(exe_ctx))) {
if (error_ptr)
error_ptr->SetErrorString("DW_OP_shr failed.");
return false;
}
}
break;
// OPCODE: DW_OP_shra
// OPERANDS: none
// DESCRIPTION: pops the top two stack entries, shifts the former second
// entry right arithmetically (divide the magnitude by 2, keep the same
// sign for the result) by the number of bits specified by the former top
// of the stack, and pushes the result.
case DW_OP_shra:
if (stack.size() < 2) {
if (error_ptr)
error_ptr->SetErrorString(
"Expression stack needs at least 2 items for DW_OP_shra.");
return false;
} else {
tmp = stack.back();
stack.pop_back();
stack.back().ResolveValue(exe_ctx) >>= tmp.ResolveValue(exe_ctx);
}
break;
// OPCODE: DW_OP_xor
// OPERANDS: none
// DESCRIPTION: pops the top two stack entries, performs the bitwise
// exclusive-or operation on the two, and pushes the result.
case DW_OP_xor:
if (stack.size() < 2) {
if (error_ptr)
error_ptr->SetErrorString(
"Expression stack needs at least 2 items for DW_OP_xor.");
return false;
} else {
tmp = stack.back();
stack.pop_back();
stack.back().ResolveValue(exe_ctx) =
stack.back().ResolveValue(exe_ctx) ^ tmp.ResolveValue(exe_ctx);
}
break;
// OPCODE: DW_OP_skip
// OPERANDS: int16_t
// DESCRIPTION: An unconditional branch. Its single operand is a 2-byte
// signed integer constant. The 2-byte constant is the number of bytes of
// the DWARF expression to skip forward or backward from the current
// operation, beginning after the 2-byte constant.
case DW_OP_skip: {
int16_t skip_offset = (int16_t)opcodes.GetU16(&offset);
lldb::offset_t new_offset = offset + skip_offset;
if (new_offset >= opcodes_offset && new_offset < end_offset)
offset = new_offset;
else {
if (error_ptr)
error_ptr->SetErrorString("Invalid opcode offset in DW_OP_skip.");
return false;
}
} break;
// OPCODE: DW_OP_bra
// OPERANDS: int16_t
// DESCRIPTION: A conditional branch. Its single operand is a 2-byte
// signed integer constant. This operation pops the top of stack. If the
// value popped is not the constant 0, the 2-byte constant operand is the
// number of bytes of the DWARF expression to skip forward or backward from
// the current operation, beginning after the 2-byte constant.
case DW_OP_bra:
if (stack.empty()) {
if (error_ptr)
error_ptr->SetErrorString(
"Expression stack needs at least 1 item for DW_OP_bra.");
return false;
} else {
tmp = stack.back();
stack.pop_back();
int16_t bra_offset = (int16_t)opcodes.GetU16(&offset);
Scalar zero(0);
if (tmp.ResolveValue(exe_ctx) != zero) {
lldb::offset_t new_offset = offset + bra_offset;
if (new_offset >= opcodes_offset && new_offset < end_offset)
offset = new_offset;
else {
if (error_ptr)
error_ptr->SetErrorString("Invalid opcode offset in DW_OP_bra.");
return false;
}
}
}
break;
// OPCODE: DW_OP_eq
// OPERANDS: none
// DESCRIPTION: pops the top two stack values, compares using the
// equals (==) operator.
// STACK RESULT: push the constant value 1 onto the stack if the result
// of the operation is true or the constant value 0 if the result of the
// operation is false.
case DW_OP_eq:
if (stack.size() < 2) {
if (error_ptr)
error_ptr->SetErrorString(
"Expression stack needs at least 2 items for DW_OP_eq.");
return false;
} else {
tmp = stack.back();
stack.pop_back();
stack.back().ResolveValue(exe_ctx) =
stack.back().ResolveValue(exe_ctx) == tmp.ResolveValue(exe_ctx);
}
break;
// OPCODE: DW_OP_ge
// OPERANDS: none
// DESCRIPTION: pops the top two stack values, compares using the
// greater than or equal to (>=) operator.
// STACK RESULT: push the constant value 1 onto the stack if the result
// of the operation is true or the constant value 0 if the result of the
// operation is false.
case DW_OP_ge:
if (stack.size() < 2) {
if (error_ptr)
error_ptr->SetErrorString(
"Expression stack needs at least 2 items for DW_OP_ge.");
return false;
} else {
tmp = stack.back();
stack.pop_back();
stack.back().ResolveValue(exe_ctx) =
stack.back().ResolveValue(exe_ctx) >= tmp.ResolveValue(exe_ctx);
}
break;
// OPCODE: DW_OP_gt
// OPERANDS: none
// DESCRIPTION: pops the top two stack values, compares using the
// greater than (>) operator.
// STACK RESULT: push the constant value 1 onto the stack if the result
// of the operation is true or the constant value 0 if the result of the
// operation is false.
case DW_OP_gt:
if (stack.size() < 2) {
if (error_ptr)
error_ptr->SetErrorString(
"Expression stack needs at least 2 items for DW_OP_gt.");
return false;
} else {
tmp = stack.back();
stack.pop_back();
stack.back().ResolveValue(exe_ctx) =
stack.back().ResolveValue(exe_ctx) > tmp.ResolveValue(exe_ctx);
}
break;
// OPCODE: DW_OP_le
// OPERANDS: none
// DESCRIPTION: pops the top two stack values, compares using the
// less than or equal to (<=) operator.
// STACK RESULT: push the constant value 1 onto the stack if the result
// of the operation is true or the constant value 0 if the result of the
// operation is false.
case DW_OP_le:
if (stack.size() < 2) {
if (error_ptr)
error_ptr->SetErrorString(
"Expression stack needs at least 2 items for DW_OP_le.");
return false;
} else {
tmp = stack.back();
stack.pop_back();
stack.back().ResolveValue(exe_ctx) =
stack.back().ResolveValue(exe_ctx) <= tmp.ResolveValue(exe_ctx);
}
break;
// OPCODE: DW_OP_lt
// OPERANDS: none
// DESCRIPTION: pops the top two stack values, compares using the
// less than (<) operator.
// STACK RESULT: push the constant value 1 onto the stack if the result
// of the operation is true or the constant value 0 if the result of the
// operation is false.
case DW_OP_lt:
if (stack.size() < 2) {
if (error_ptr)
error_ptr->SetErrorString(
"Expression stack needs at least 2 items for DW_OP_lt.");
return false;
} else {
tmp = stack.back();
stack.pop_back();
stack.back().ResolveValue(exe_ctx) =
stack.back().ResolveValue(exe_ctx) < tmp.ResolveValue(exe_ctx);
}
break;
// OPCODE: DW_OP_ne
// OPERANDS: none
// DESCRIPTION: pops the top two stack values, compares using the
// not equal (!=) operator.
// STACK RESULT: push the constant value 1 onto the stack if the result
// of the operation is true or the constant value 0 if the result of the
// operation is false.
case DW_OP_ne:
if (stack.size() < 2) {
if (error_ptr)
error_ptr->SetErrorString(
"Expression stack needs at least 2 items for DW_OP_ne.");
return false;
} else {
tmp = stack.back();
stack.pop_back();
stack.back().ResolveValue(exe_ctx) =
stack.back().ResolveValue(exe_ctx) != tmp.ResolveValue(exe_ctx);
}
break;
// OPCODE: DW_OP_litn
// OPERANDS: none
// DESCRIPTION: encode the unsigned literal values from 0 through 31.
// STACK RESULT: push the unsigned literal constant value onto the top
// of the stack.
case DW_OP_lit0:
case DW_OP_lit1:
case DW_OP_lit2:
case DW_OP_lit3:
case DW_OP_lit4:
case DW_OP_lit5:
case DW_OP_lit6:
case DW_OP_lit7:
case DW_OP_lit8:
case DW_OP_lit9:
case DW_OP_lit10:
case DW_OP_lit11:
case DW_OP_lit12:
case DW_OP_lit13:
case DW_OP_lit14:
case DW_OP_lit15:
case DW_OP_lit16:
case DW_OP_lit17:
case DW_OP_lit18:
case DW_OP_lit19:
case DW_OP_lit20:
case DW_OP_lit21:
case DW_OP_lit22:
case DW_OP_lit23:
case DW_OP_lit24:
case DW_OP_lit25:
case DW_OP_lit26:
case DW_OP_lit27:
case DW_OP_lit28:
case DW_OP_lit29:
case DW_OP_lit30:
case DW_OP_lit31:
stack.push_back(Scalar((uint64_t)(op - DW_OP_lit0)));
break;
// OPCODE: DW_OP_regN
// OPERANDS: none
// DESCRIPTION: Push the value in register n on the top of the stack.
case DW_OP_reg0:
case DW_OP_reg1:
case DW_OP_reg2:
case DW_OP_reg3:
case DW_OP_reg4:
case DW_OP_reg5:
case DW_OP_reg6:
case DW_OP_reg7:
case DW_OP_reg8:
case DW_OP_reg9:
case DW_OP_reg10:
case DW_OP_reg11:
case DW_OP_reg12:
case DW_OP_reg13:
case DW_OP_reg14:
case DW_OP_reg15:
case DW_OP_reg16:
case DW_OP_reg17:
case DW_OP_reg18:
case DW_OP_reg19:
case DW_OP_reg20:
case DW_OP_reg21:
case DW_OP_reg22:
case DW_OP_reg23:
case DW_OP_reg24:
case DW_OP_reg25:
case DW_OP_reg26:
case DW_OP_reg27:
case DW_OP_reg28:
case DW_OP_reg29:
case DW_OP_reg30:
case DW_OP_reg31: {
reg_num = op - DW_OP_reg0;
if (ReadRegisterValueAsScalar(reg_ctx, reg_kind, reg_num, error_ptr, tmp))
stack.push_back(tmp);
else
return false;
} break;
// OPCODE: DW_OP_regx
// OPERANDS:
// ULEB128 literal operand that encodes the register.
// DESCRIPTION: Push the value in register on the top of the stack.
case DW_OP_regx: {
reg_num = opcodes.GetULEB128(&offset);
if (ReadRegisterValueAsScalar(reg_ctx, reg_kind, reg_num, error_ptr, tmp))
stack.push_back(tmp);
else
return false;
} break;
// OPCODE: DW_OP_bregN
// OPERANDS:
// SLEB128 offset from register N
// DESCRIPTION: Value is in memory at the address specified by register
// N plus an offset.
case DW_OP_breg0:
case DW_OP_breg1:
case DW_OP_breg2:
case DW_OP_breg3:
case DW_OP_breg4:
case DW_OP_breg5:
case DW_OP_breg6:
case DW_OP_breg7:
case DW_OP_breg8:
case DW_OP_breg9:
case DW_OP_breg10:
case DW_OP_breg11:
case DW_OP_breg12:
case DW_OP_breg13:
case DW_OP_breg14:
case DW_OP_breg15:
case DW_OP_breg16:
case DW_OP_breg17:
case DW_OP_breg18:
case DW_OP_breg19:
case DW_OP_breg20:
case DW_OP_breg21:
case DW_OP_breg22:
case DW_OP_breg23:
case DW_OP_breg24:
case DW_OP_breg25:
case DW_OP_breg26:
case DW_OP_breg27:
case DW_OP_breg28:
case DW_OP_breg29:
case DW_OP_breg30:
case DW_OP_breg31: {
reg_num = op - DW_OP_breg0;
if (ReadRegisterValueAsScalar(reg_ctx, reg_kind, reg_num, error_ptr,
tmp)) {
int64_t breg_offset = opcodes.GetSLEB128(&offset);
tmp.ResolveValue(exe_ctx) += (uint64_t)breg_offset;
tmp.ClearContext();
stack.push_back(tmp);
stack.back().SetValueType(Value::eValueTypeLoadAddress);
} else
return false;
} break;
// OPCODE: DW_OP_bregx
// OPERANDS: 2
// ULEB128 literal operand that encodes the register.
// SLEB128 offset from register N
// DESCRIPTION: Value is in memory at the address specified by register
// N plus an offset.
case DW_OP_bregx: {
reg_num = opcodes.GetULEB128(&offset);
if (ReadRegisterValueAsScalar(reg_ctx, reg_kind, reg_num, error_ptr,
tmp)) {
int64_t breg_offset = opcodes.GetSLEB128(&offset);
tmp.ResolveValue(exe_ctx) += (uint64_t)breg_offset;
tmp.ClearContext();
stack.push_back(tmp);
stack.back().SetValueType(Value::eValueTypeLoadAddress);
} else
return false;
} break;
case DW_OP_fbreg:
if (exe_ctx) {
if (frame) {
Scalar value;
if (frame->GetFrameBaseValue(value, error_ptr)) {
int64_t fbreg_offset = opcodes.GetSLEB128(&offset);
value += fbreg_offset;
stack.push_back(value);
stack.back().SetValueType(Value::eValueTypeLoadAddress);
} else
return false;
} else {
if (error_ptr)
error_ptr->SetErrorString(
"Invalid stack frame in context for DW_OP_fbreg opcode.");
return false;
}
} else {
if (error_ptr)
error_ptr->SetErrorStringWithFormat(
"NULL execution context for DW_OP_fbreg.\n");
return false;
}
break;
// OPCODE: DW_OP_nop
// OPERANDS: none
// DESCRIPTION: A place holder. It has no effect on the location stack
// or any of its values.
case DW_OP_nop:
break;
// OPCODE: DW_OP_piece
// OPERANDS: 1
// ULEB128: byte size of the piece
// DESCRIPTION: The operand describes the size in bytes of the piece of
// the object referenced by the DWARF expression whose result is at the top
// of the stack. If the piece is located in a register, but does not occupy
// the entire register, the placement of the piece within that register is
// defined by the ABI.
//
// Many compilers store a single variable in sets of registers, or store a
// variable partially in memory and partially in registers. DW_OP_piece
// provides a way of describing how large a part of a variable a particular
// DWARF expression refers to.
case DW_OP_piece: {
const uint64_t piece_byte_size = opcodes.GetULEB128(&offset);
if (piece_byte_size > 0) {
Value curr_piece;
if (stack.empty()) {
// In a multi-piece expression, this means that the current piece is
// not available. Fill with zeros for now by resizing the data and
// appending it
curr_piece.ResizeData(piece_byte_size);
::memset(curr_piece.GetBuffer().GetBytes(), 0, piece_byte_size);
pieces.AppendDataToHostBuffer(curr_piece);
} else {
Status error;
// Extract the current piece into "curr_piece"
Value curr_piece_source_value(stack.back());
stack.pop_back();
const Value::ValueType curr_piece_source_value_type =
curr_piece_source_value.GetValueType();
switch (curr_piece_source_value_type) {
case Value::eValueTypeLoadAddress:
if (process) {
if (curr_piece.ResizeData(piece_byte_size) == piece_byte_size) {
lldb::addr_t load_addr =
curr_piece_source_value.GetScalar().ULongLong(
LLDB_INVALID_ADDRESS);
if (process->ReadMemory(
load_addr, curr_piece.GetBuffer().GetBytes(),
piece_byte_size, error) != piece_byte_size) {
if (error_ptr)
error_ptr->SetErrorStringWithFormat(
"failed to read memory DW_OP_piece(%" PRIu64
") from 0x%" PRIx64,
piece_byte_size, load_addr);
return false;
}
} else {
if (error_ptr)
error_ptr->SetErrorStringWithFormat(
"failed to resize the piece memory buffer for "
"DW_OP_piece(%" PRIu64 ")",
piece_byte_size);
return false;
}
}
break;
case Value::eValueTypeFileAddress:
case Value::eValueTypeHostAddress:
if (error_ptr) {
lldb::addr_t addr = curr_piece_source_value.GetScalar().ULongLong(
LLDB_INVALID_ADDRESS);
error_ptr->SetErrorStringWithFormat(
"failed to read memory DW_OP_piece(%" PRIu64
") from %s address 0x%" PRIx64,
piece_byte_size, curr_piece_source_value.GetValueType() ==
Value::eValueTypeFileAddress
? "file"
: "host",
addr);
}
return false;
case Value::eValueTypeScalar: {
uint32_t bit_size = piece_byte_size * 8;
uint32_t bit_offset = 0;
if (!curr_piece_source_value.GetScalar().ExtractBitfield(
bit_size, bit_offset)) {
if (error_ptr)
error_ptr->SetErrorStringWithFormat(
"unable to extract %" PRIu64 " bytes from a %" PRIu64
" byte scalar value.",
piece_byte_size,
(uint64_t)curr_piece_source_value.GetScalar()
.GetByteSize());
return false;
}
curr_piece = curr_piece_source_value;
} break;
case Value::eValueTypeVector: {
if (curr_piece_source_value.GetVector().length >= piece_byte_size)
curr_piece_source_value.GetVector().length = piece_byte_size;
else {
if (error_ptr)
error_ptr->SetErrorStringWithFormat(
"unable to extract %" PRIu64 " bytes from a %" PRIu64
" byte vector value.",
piece_byte_size,
(uint64_t)curr_piece_source_value.GetVector().length);
return false;
}
} break;
}
// Check if this is the first piece?
if (op_piece_offset == 0) {
// This is the first piece, we should push it back onto the stack
// so subsequent pieces will be able to access this piece and add
// to it
if (pieces.AppendDataToHostBuffer(curr_piece) == 0) {
if (error_ptr)
error_ptr->SetErrorString("failed to append piece data");
return false;
}
} else {
// If this is the second or later piece there should be a value on
// the stack
if (pieces.GetBuffer().GetByteSize() != op_piece_offset) {
if (error_ptr)
error_ptr->SetErrorStringWithFormat(
"DW_OP_piece for offset %" PRIu64
" but top of stack is of size %" PRIu64,
op_piece_offset, pieces.GetBuffer().GetByteSize());
return false;
}
if (pieces.AppendDataToHostBuffer(curr_piece) == 0) {
if (error_ptr)
error_ptr->SetErrorString("failed to append piece data");
return false;
}
}
op_piece_offset += piece_byte_size;
}
}
} break;
case DW_OP_bit_piece: // 0x9d ULEB128 bit size, ULEB128 bit offset (DWARF3);
if (stack.size() < 1) {
if (error_ptr)
error_ptr->SetErrorString(
"Expression stack needs at least 1 item for DW_OP_bit_piece.");
return false;
} else {
const uint64_t piece_bit_size = opcodes.GetULEB128(&offset);
const uint64_t piece_bit_offset = opcodes.GetULEB128(&offset);
switch (stack.back().GetValueType()) {
case Value::eValueTypeScalar: {
if (!stack.back().GetScalar().ExtractBitfield(piece_bit_size,
piece_bit_offset)) {
if (error_ptr)
error_ptr->SetErrorStringWithFormat(
"unable to extract %" PRIu64 " bit value with %" PRIu64
" bit offset from a %" PRIu64 " bit scalar value.",
piece_bit_size, piece_bit_offset,
(uint64_t)(stack.back().GetScalar().GetByteSize() * 8));
return false;
}
} break;
case Value::eValueTypeFileAddress:
case Value::eValueTypeLoadAddress:
case Value::eValueTypeHostAddress:
if (error_ptr) {
error_ptr->SetErrorStringWithFormat(
"unable to extract DW_OP_bit_piece(bit_size = %" PRIu64
", bit_offset = %" PRIu64 ") from an address value.",
piece_bit_size, piece_bit_offset);
}
return false;
case Value::eValueTypeVector:
if (error_ptr) {
error_ptr->SetErrorStringWithFormat(
"unable to extract DW_OP_bit_piece(bit_size = %" PRIu64
", bit_offset = %" PRIu64 ") from a vector value.",
piece_bit_size, piece_bit_offset);
}
return false;
}
}
break;
// OPCODE: DW_OP_push_object_address
// OPERANDS: none
// DESCRIPTION: Pushes the address of the object currently being
// evaluated as part of evaluation of a user presented expression. This
// object may correspond to an independent variable described by its own
// DIE or it may be a component of an array, structure, or class whose
// address has been dynamically determined by an earlier step during user
// expression evaluation.
case DW_OP_push_object_address:
if (object_address_ptr)
stack.push_back(*object_address_ptr);
else {
if (error_ptr)
error_ptr->SetErrorString("DW_OP_push_object_address used without "
"specifying an object address");
return false;
}
break;
// OPCODE: DW_OP_call2
// OPERANDS:
// uint16_t compile unit relative offset of a DIE
// DESCRIPTION: Performs subroutine calls during evaluation
// of a DWARF expression. The operand is the 2-byte unsigned offset of a
// debugging information entry in the current compilation unit.
//
// Operand interpretation is exactly like that for DW_FORM_ref2.
//
// This operation transfers control of DWARF expression evaluation to the
// DW_AT_location attribute of the referenced DIE. If there is no such
// attribute, then there is no effect. Execution of the DWARF expression of
// a DW_AT_location attribute may add to and/or remove from values on the
// stack. Execution returns to the point following the call when the end of