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[lldb] Add missing operations to GetOpcodeDataSize #120163

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merged 2 commits into from
Jan 23, 2025
Merged

[lldb] Add missing operations to GetOpcodeDataSize #120163

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21c9bbb
[lldb] Add missing operations to GetOpcodeDataSize
JDevlieghere Jan 23, 2025
19aeb5e
Fix DW_OP_implicit_pointer
JDevlieghere Jan 23, 2025
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75 changes: 62 additions & 13 deletions lldb/source/Expression/DWARFExpression.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -132,10 +132,35 @@ static llvm::Error ReadRegisterValueAsScalar(RegisterContext *reg_ctx,
/// are made on the state of \p data after this call.
static lldb::offset_t GetOpcodeDataSize(const DataExtractor &data,
const lldb::offset_t data_offset,
const uint8_t op,
const LocationAtom op,
const DWARFUnit *dwarf_cu) {
lldb::offset_t offset = data_offset;
switch (op) {
// Only used in LLVM metadata.
case DW_OP_LLVM_fragment:
case DW_OP_LLVM_convert:
case DW_OP_LLVM_tag_offset:
case DW_OP_LLVM_entry_value:
case DW_OP_LLVM_implicit_pointer:
case DW_OP_LLVM_arg:
case DW_OP_LLVM_extract_bits_sext:
case DW_OP_LLVM_extract_bits_zext:
break;
// Vendor extensions:
case DW_OP_HP_is_value:
case DW_OP_HP_fltconst4:
case DW_OP_HP_fltconst8:
case DW_OP_HP_mod_range:
case DW_OP_HP_unmod_range:
case DW_OP_HP_tls:
case DW_OP_INTEL_bit_piece:
case DW_OP_WASM_location:
case DW_OP_WASM_location_int:
case DW_OP_APPLE_uninit:
case DW_OP_PGI_omp_thread_num:
case DW_OP_hi_user:
break;

case DW_OP_addr:
case DW_OP_call_ref: // 0x9a 1 address sized offset of DIE (DWARF3)
return data.GetAddressByteSize();
Expand Down Expand Up @@ -246,6 +271,7 @@ static lldb::offset_t GetOpcodeDataSize(const DataExtractor &data,
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
case DW_OP_deref_type: // 0xa6 1 1-byte constant
return 1;

// Opcodes with a single 2 byte arguments
Expand All @@ -268,7 +294,6 @@ static lldb::offset_t GetOpcodeDataSize(const DataExtractor &data,
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
Expand Down Expand Up @@ -307,14 +332,20 @@ static lldb::offset_t GetOpcodeDataSize(const DataExtractor &data,
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_convert: // 0xa8 1 ULEB128 offset
case DW_OP_reinterpret: // 0xa9 1 ULEB128 offset
case DW_OP_addrx: // 0xa1 1 ULEB128 index
case DW_OP_constx: // 0xa2 1 ULEB128 index
case DW_OP_xderef_type: // 0xa7 1 ULEB128 index
case DW_OP_GNU_addr_index: // 0xfb 1 ULEB128 index
case DW_OP_GNU_const_index: // 0xfc 1 ULEB128 index
data.Skip_LEB128(&offset);
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Should we list all values explicitly and get rid of the default so we get a warning about missing entries in the future?

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);
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);
case DW_OP_regval_type: // 0xa5 ULEB128 + ULEB128
data.Skip_LEB128(&offset);
data.Skip_LEB128(&offset);
return offset - data_offset;
Expand All @@ -327,27 +358,45 @@ static lldb::offset_t GetOpcodeDataSize(const DataExtractor &data,
return offset - data_offset;
}

case DW_OP_implicit_pointer: // 0xa0 4 + LEB128
{
data.Skip_LEB128(&offset);
return 4 + offset - data_offset;
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The first operand is a 4-byte unsigned value in the 32-bit DWARF format, or an 8-byte unsigned value in the 64-bit DWARF format

}

case DW_OP_GNU_entry_value:
case DW_OP_entry_value: // 0xa3 ULEB128 size + variable-length block
{
uint64_t subexpr_len = data.GetULEB128(&offset);
return (offset - data_offset) + subexpr_len;
}

default:
if (!dwarf_cu) {
return LLDB_INVALID_OFFSET;
}
case DW_OP_const_type: // 0xa4 ULEB128 + size + variable-length block
{
data.Skip_LEB128(&offset);
uint8_t length = data.GetU8(&offset);
return (offset - data_offset) + length;
}

case DW_OP_LLVM_user: // 0xe9: ULEB128 + variable length constant
{
uint64_t constants = data.GetULEB128(&offset);
return (offset - data_offset) + constants;
}
}

if (dwarf_cu)
return dwarf_cu->GetSymbolFileDWARF().GetVendorDWARFOpcodeSize(
data, data_offset, op);
}

return LLDB_INVALID_OFFSET;
}

llvm::Expected<lldb::addr_t>
DWARFExpression::GetLocation_DW_OP_addr(const DWARFUnit *dwarf_cu) const {
lldb::offset_t offset = 0;
while (m_data.ValidOffset(offset)) {
const uint8_t op = m_data.GetU8(&offset);
const LocationAtom op = static_cast<LocationAtom>(m_data.GetU8(&offset));

if (op == DW_OP_addr)
return m_data.GetAddress(&offset);
Expand Down Expand Up @@ -376,7 +425,7 @@ bool DWARFExpression::Update_DW_OP_addr(const DWARFUnit *dwarf_cu,
lldb::addr_t file_addr) {
lldb::offset_t offset = 0;
while (m_data.ValidOffset(offset)) {
const uint8_t op = m_data.GetU8(&offset);
const LocationAtom op = static_cast<LocationAtom>(m_data.GetU8(&offset));

if (op == DW_OP_addr) {
const uint32_t addr_byte_size = m_data.GetAddressByteSize();
Expand Down Expand Up @@ -434,7 +483,7 @@ bool DWARFExpression::ContainsThreadLocalStorage(
const DWARFUnit *dwarf_cu) const {
lldb::offset_t offset = 0;
while (m_data.ValidOffset(offset)) {
const uint8_t op = m_data.GetU8(&offset);
const LocationAtom op = static_cast<LocationAtom>(m_data.GetU8(&offset));

if (op == DW_OP_form_tls_address || op == DW_OP_GNU_push_tls_address)
return true;
Expand Down Expand Up @@ -465,7 +514,7 @@ bool DWARFExpression::LinkThreadLocalStorage(
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);
const LocationAtom op = static_cast<LocationAtom>(m_data.GetU8(&offset));

bool decoded_data = false;
switch (op) {
Expand Down
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