[Lldb-commits] [lldb] [lldb] Add missing operations to GetOpcodeDataSize (PR #120163)
Jonas Devlieghere via lldb-commits
lldb-commits at lists.llvm.org
Thu Jan 23 09:37:12 PST 2025
https://github.com/JDevlieghere updated https://github.com/llvm/llvm-project/pull/120163
>From 21c9bbb7edab88caeb1b121dfe9090a6a3ef4404 Mon Sep 17 00:00:00 2001
From: Jonas Devlieghere <jonas at devlieghere.com>
Date: Wed, 22 Jan 2025 17:36:24 -0800
Subject: [PATCH 1/2] [lldb] Add missing operations to GetOpcodeDataSize
The improved error reporting in #120162 revealed that we were missing
opcodes in GetOpcodeDataSize. I changed the function to remove the
default case and switch over the enum type which will cause the compiler
to emit a warning if there are unhandled operations in the future.
rdar://139705570
---
lldb/source/Expression/DWARFExpression.cpp | 75 ++++++++++++++++++----
1 file changed, 62 insertions(+), 13 deletions(-)
diff --git a/lldb/source/Expression/DWARFExpression.cpp b/lldb/source/Expression/DWARFExpression.cpp
index 1d826e341e2c44..072cc74bbaafea 100644
--- a/lldb/source/Expression/DWARFExpression.cpp
+++ b/lldb/source/Expression/DWARFExpression.cpp
@@ -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();
@@ -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
@@ -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
@@ -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);
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;
@@ -327,6 +358,12 @@ 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;
+ }
+
case DW_OP_GNU_entry_value:
case DW_OP_entry_value: // 0xa3 ULEB128 size + variable-length block
{
@@ -334,20 +371,32 @@ static lldb::offset_t GetOpcodeDataSize(const DataExtractor &data,
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);
@@ -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();
@@ -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;
@@ -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) {
>From 19aeb5e27b9b849fd2d722c4cdd9e8c1b1cbffd9 Mon Sep 17 00:00:00 2001
From: Jonas Devlieghere <jonas at devlieghere.com>
Date: Thu, 23 Jan 2025 09:36:40 -0800
Subject: [PATCH 2/2] Fix DW_OP_implicit_pointer
---
lldb/source/Expression/DWARFExpression.cpp | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/lldb/source/Expression/DWARFExpression.cpp b/lldb/source/Expression/DWARFExpression.cpp
index 072cc74bbaafea..f48f3ab9307dd1 100644
--- a/lldb/source/Expression/DWARFExpression.cpp
+++ b/lldb/source/Expression/DWARFExpression.cpp
@@ -358,10 +358,11 @@ static lldb::offset_t GetOpcodeDataSize(const DataExtractor &data,
return offset - data_offset;
}
- case DW_OP_implicit_pointer: // 0xa0 4 + LEB128
+ case DW_OP_implicit_pointer: // 0xa0 4-byte (or 8-byte for DWARF 64) constant
+ // + LEB128
{
data.Skip_LEB128(&offset);
- return 4 + offset - data_offset;
+ return DWARFUnit::GetAddressByteSize(dwarf_cu) + offset - data_offset;
}
case DW_OP_GNU_entry_value:
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