https://github.com/labath updated
https://github.com/llvm/llvm-project/pull/128874
>From 51e6692e62331b801fe23217c21657e6365179d1 Mon Sep 17 00:00:00 2001
From: Pavel Labath <pa...@labath.sk>
Date: Wed, 26 Feb 2025 14:42:14 +0100
Subject: [PATCH] [lldb] Deindent UnwindAssemblyInstEmulation
by two levels using early returns.
---
.../UnwindAssemblyInstEmulation.cpp | 438 +++++++++---------
1 file changed, 211 insertions(+), 227 deletions(-)
diff --git
a/lldb/source/Plugins/UnwindAssembly/InstEmulation/UnwindAssemblyInstEmulation.cpp
b/lldb/source/Plugins/UnwindAssembly/InstEmulation/UnwindAssemblyInstEmulation.cpp
index 502231002f7f4..3988dcb50f353 100644
---
a/lldb/source/Plugins/UnwindAssembly/InstEmulation/UnwindAssemblyInstEmulation.cpp
+++
b/lldb/source/Plugins/UnwindAssembly/InstEmulation/UnwindAssemblyInstEmulation.cpp
@@ -56,251 +56,235 @@ bool
UnwindAssemblyInstEmulation::GetNonCallSiteUnwindPlanFromAssembly(
if (opcode_data == nullptr || opcode_size == 0)
return false;
- if (range.GetByteSize() > 0 && range.GetBaseAddress().IsValid() &&
- m_inst_emulator_up.get()) {
+ if (range.GetByteSize() == 0 || !range.GetBaseAddress().IsValid() ||
+ !m_inst_emulator_up)
+ return false;
- // The instruction emulation subclass setup the unwind plan for the first
- // instruction.
- m_inst_emulator_up->CreateFunctionEntryUnwind(unwind_plan);
+ // The instruction emulation subclass setup the unwind plan for the first
+ // instruction.
+ m_inst_emulator_up->CreateFunctionEntryUnwind(unwind_plan);
- // CreateFunctionEntryUnwind should have created the first row. If it
- // doesn't, then we are done.
- if (unwind_plan.GetRowCount() == 0)
- return false;
+ // CreateFunctionEntryUnwind should have created the first row. If it
doesn't,
+ // then we are done.
+ if (unwind_plan.GetRowCount() == 0)
+ return false;
- const bool prefer_file_cache = true;
- DisassemblerSP disasm_sp(Disassembler::DisassembleBytes(
- m_arch, nullptr, nullptr, nullptr, nullptr, range.GetBaseAddress(),
- opcode_data, opcode_size, 99999, prefer_file_cache));
+ const bool prefer_file_cache = true;
+ DisassemblerSP disasm_sp(Disassembler::DisassembleBytes(
+ m_arch, nullptr, nullptr, nullptr, nullptr, range.GetBaseAddress(),
+ opcode_data, opcode_size, 99999, prefer_file_cache));
- Log *log = GetLog(LLDBLog::Unwind);
+ if (!disasm_sp)
+ return false;
- if (disasm_sp) {
+ Log *log = GetLog(LLDBLog::Unwind);
- m_range_ptr = ⦥
- m_unwind_plan_ptr = &unwind_plan;
+ m_range_ptr = ⦥
+ m_unwind_plan_ptr = &unwind_plan;
+
+ const uint32_t addr_byte_size = m_arch.GetAddressByteSize();
+ const bool show_address = true;
+ const bool show_bytes = true;
+ const bool show_control_flow_kind = false;
+ m_cfa_reg_info = *m_inst_emulator_up->GetRegisterInfo(
+ unwind_plan.GetRegisterKind(), unwind_plan.GetInitialCFARegister());
+ m_fp_is_cfa = false;
+ m_register_values.clear();
+ m_pushed_regs.clear();
+
+ // Initialize the CFA with a known value. In the 32 bit case it will be
+ // 0x80000000, and in the 64 bit case 0x8000000000000000. We use the address
+ // byte size to be safe for any future address sizes
+ m_initial_sp = (1ull << ((addr_byte_size * 8) - 1));
+ RegisterValue cfa_reg_value;
+ cfa_reg_value.SetUInt(m_initial_sp, m_cfa_reg_info.byte_size);
+ SetRegisterValue(m_cfa_reg_info, cfa_reg_value);
+
+ const InstructionList &inst_list = disasm_sp->GetInstructionList();
+ const size_t num_instructions = inst_list.GetSize();
+
+ if (num_instructions > 0) {
+ Instruction *inst = inst_list.GetInstructionAtIndex(0).get();
+ const lldb::addr_t base_addr = inst->GetAddress().GetFileAddress();
+
+ // Map for storing the unwind plan row and the value of the registers at a
+ // given offset. When we see a forward branch we add a new entry to this
map
+ // with the actual unwind plan row and register context for the target
+ // address of the branch as the current data have to be valid for the
target
+ // address of the branch too if we are in the same function.
+ std::map<lldb::addr_t, std::pair<UnwindPlan::RowSP, RegisterValueMap>>
+ saved_unwind_states;
+
+ // Make a copy of the current instruction Row and save it in m_curr_row so
+ // we can add updates as we process the instructions.
+ UnwindPlan::RowSP last_row =
+ std::make_shared<UnwindPlan::Row>(*unwind_plan.GetLastRow());
+ m_curr_row = std::make_shared<UnwindPlan::Row>(*last_row);
+
+ // Add the initial state to the save list with offset 0.
+ saved_unwind_states.insert({0, {last_row, m_register_values}});
+
+ // cache the stack pointer register number (in whatever register numbering
+ // this UnwindPlan uses) for quick reference during instruction parsing.
+ RegisterInfo sp_reg_info = *m_inst_emulator_up->GetRegisterInfo(
+ eRegisterKindGeneric, LLDB_REGNUM_GENERIC_SP);
+
+ // The architecture dependent condition code of the last processed
+ // instruction.
+ EmulateInstruction::InstructionCondition last_condition =
+ EmulateInstruction::UnconditionalCondition;
+ lldb::addr_t condition_block_start_offset = 0;
+
+ for (size_t idx = 0; idx < num_instructions; ++idx) {
+ m_curr_row_modified = false;
+ m_forward_branch_offset = 0;
+
+ inst = inst_list.GetInstructionAtIndex(idx).get();
+ if (inst) {
+ lldb::addr_t current_offset =
+ inst->GetAddress().GetFileAddress() - base_addr;
+ auto it = saved_unwind_states.upper_bound(current_offset);
+ assert(it != saved_unwind_states.begin() &&
+ "Unwind row for the function entry missing");
+ --it; // Move it to the row corresponding to the current offset
+
+ // If the offset of m_curr_row don't match with the offset we see in
+ // saved_unwind_states then we have to update m_curr_row and
+ // m_register_values based on the saved values. It is happening after
we
+ // processed an epilogue and a return to caller instruction.
+ if (it->second.first->GetOffset() != m_curr_row->GetOffset()) {
+ UnwindPlan::Row *newrow = new UnwindPlan::Row;
+ *newrow = *it->second.first;
+ m_curr_row.reset(newrow);
+ m_register_values = it->second.second;
+ // re-set the CFA register ivars to match the new m_curr_row.
+ if (sp_reg_info.name &&
+ m_curr_row->GetCFAValue().IsRegisterPlusOffset()) {
+ uint32_t row_cfa_regnum =
+ m_curr_row->GetCFAValue().GetRegisterNumber();
+ lldb::RegisterKind row_kind = m_unwind_plan_ptr->GetRegisterKind();
+ // set m_cfa_reg_info to the row's CFA reg.
+ m_cfa_reg_info =
+ *m_inst_emulator_up->GetRegisterInfo(row_kind, row_cfa_regnum);
+ // set m_fp_is_cfa.
+ if (sp_reg_info.kinds[row_kind] == row_cfa_regnum)
+ m_fp_is_cfa = false;
+ else
+ m_fp_is_cfa = true;
+ }
+ }
- const uint32_t addr_byte_size = m_arch.GetAddressByteSize();
- const bool show_address = true;
- const bool show_bytes = true;
- const bool show_control_flow_kind = false;
- m_cfa_reg_info = *m_inst_emulator_up->GetRegisterInfo(
- unwind_plan.GetRegisterKind(), unwind_plan.GetInitialCFARegister());
- m_fp_is_cfa = false;
- m_register_values.clear();
- m_pushed_regs.clear();
-
- // Initialize the CFA with a known value. In the 32 bit case it will be
- // 0x80000000, and in the 64 bit case 0x8000000000000000. We use the
- // address byte size to be safe for any future address sizes
- m_initial_sp = (1ull << ((addr_byte_size * 8) - 1));
- RegisterValue cfa_reg_value;
- cfa_reg_value.SetUInt(m_initial_sp, m_cfa_reg_info.byte_size);
- SetRegisterValue(m_cfa_reg_info, cfa_reg_value);
-
- const InstructionList &inst_list = disasm_sp->GetInstructionList();
- const size_t num_instructions = inst_list.GetSize();
-
- if (num_instructions > 0) {
- Instruction *inst = inst_list.GetInstructionAtIndex(0).get();
- const lldb::addr_t base_addr = inst->GetAddress().GetFileAddress();
-
- // Map for storing the unwind plan row and the value of the registers
- // at a given offset. When we see a forward branch we add a new entry
- // to this map with the actual unwind plan row and register context for
- // the target address of the branch as the current data have to be
- // valid for the target address of the branch too if we are in the same
- // function.
- std::map<lldb::addr_t, std::pair<UnwindPlan::RowSP, RegisterValueMap>>
- saved_unwind_states;
-
- // Make a copy of the current instruction Row and save it in m_curr_row
- // so we can add updates as we process the instructions.
- UnwindPlan::RowSP last_row =
- std::make_shared<UnwindPlan::Row>(*unwind_plan.GetLastRow());
- m_curr_row = std::make_shared<UnwindPlan::Row>(*last_row);
-
- // Add the initial state to the save list with offset 0.
- saved_unwind_states.insert({0, {last_row, m_register_values}});
-
- // cache the stack pointer register number (in whatever register
- // numbering this UnwindPlan uses) for quick reference during
- // instruction parsing.
- RegisterInfo sp_reg_info = *m_inst_emulator_up->GetRegisterInfo(
- eRegisterKindGeneric, LLDB_REGNUM_GENERIC_SP);
-
- // The architecture dependent condition code of the last processed
- // instruction.
- EmulateInstruction::InstructionCondition last_condition =
- EmulateInstruction::UnconditionalCondition;
- lldb::addr_t condition_block_start_offset = 0;
-
- for (size_t idx = 0; idx < num_instructions; ++idx) {
- m_curr_row_modified = false;
- m_forward_branch_offset = 0;
-
- inst = inst_list.GetInstructionAtIndex(idx).get();
- if (inst) {
- lldb::addr_t current_offset =
- inst->GetAddress().GetFileAddress() - base_addr;
- auto it = saved_unwind_states.upper_bound(current_offset);
- assert(it != saved_unwind_states.begin() &&
- "Unwind row for the function entry missing");
- --it; // Move it to the row corresponding to the current offset
-
- // If the offset of m_curr_row don't match with the offset we see
- // in saved_unwind_states then we have to update m_curr_row and
- // m_register_values based on the saved values. It is happening
- // after we processed an epilogue and a return to caller
- // instruction.
- if (it->second.first->GetOffset() != m_curr_row->GetOffset()) {
- UnwindPlan::Row *newrow = new UnwindPlan::Row;
- *newrow = *it->second.first;
- m_curr_row.reset(newrow);
- m_register_values = it->second.second;
- // re-set the CFA register ivars to match the
- // new m_curr_row.
- if (sp_reg_info.name &&
- m_curr_row->GetCFAValue().IsRegisterPlusOffset()) {
- uint32_t row_cfa_regnum =
- m_curr_row->GetCFAValue().GetRegisterNumber();
- lldb::RegisterKind row_kind =
- m_unwind_plan_ptr->GetRegisterKind();
- // set m_cfa_reg_info to the row's CFA reg.
- m_cfa_reg_info = *m_inst_emulator_up->GetRegisterInfo(
- row_kind, row_cfa_regnum);
- // set m_fp_is_cfa.
- if (sp_reg_info.kinds[row_kind] == row_cfa_regnum)
- m_fp_is_cfa = false;
- else
- m_fp_is_cfa = true;
- }
- }
+ m_inst_emulator_up->SetInstruction(inst->GetOpcode(),
+ inst->GetAddress(), nullptr);
+
+ if (last_condition != m_inst_emulator_up->GetInstructionCondition()) {
+ if (m_inst_emulator_up->GetInstructionCondition() !=
+ EmulateInstruction::UnconditionalCondition &&
+ saved_unwind_states.count(current_offset) == 0) {
+ // If we don't have a saved row for the current offset then save
our
+ // current state because we will have to restore it after the
+ // conditional block.
+ auto new_row =
std::make_shared<UnwindPlan::Row>(*m_curr_row.get());
+ saved_unwind_states.insert(
+ {current_offset, {new_row, m_register_values}});
+ }
- m_inst_emulator_up->SetInstruction(inst->GetOpcode(),
- inst->GetAddress(), nullptr);
-
- if (last_condition !=
- m_inst_emulator_up->GetInstructionCondition()) {
- if (m_inst_emulator_up->GetInstructionCondition() !=
- EmulateInstruction::UnconditionalCondition &&
- saved_unwind_states.count(current_offset) == 0) {
- // If we don't have a saved row for the current offset then
- // save our current state because we will have to restore it
- // after the conditional block.
- auto new_row =
- std::make_shared<UnwindPlan::Row>(*m_curr_row.get());
- saved_unwind_states.insert(
- {current_offset, {new_row, m_register_values}});
- }
-
- // If the last instruction was conditional with a different
- // condition then the then current condition then restore the
- // condition.
- if (last_condition !=
- EmulateInstruction::UnconditionalCondition) {
- const auto &saved_state =
- saved_unwind_states.at(condition_block_start_offset);
- m_curr_row =
- std::make_shared<UnwindPlan::Row>(*saved_state.first);
- m_curr_row->SetOffset(current_offset);
- m_register_values = saved_state.second;
- // re-set the CFA register ivars to match the
- // new m_curr_row.
- if (sp_reg_info.name &&
- m_curr_row->GetCFAValue().IsRegisterPlusOffset()) {
- uint32_t row_cfa_regnum =
- m_curr_row->GetCFAValue().GetRegisterNumber();
- lldb::RegisterKind row_kind =
- m_unwind_plan_ptr->GetRegisterKind();
- // set m_cfa_reg_info to the row's CFA reg.
- m_cfa_reg_info = *m_inst_emulator_up->GetRegisterInfo(
- row_kind, row_cfa_regnum);
- // set m_fp_is_cfa.
- if (sp_reg_info.kinds[row_kind] == row_cfa_regnum)
- m_fp_is_cfa = false;
- else
- m_fp_is_cfa = true;
- }
- bool replace_existing =
- true; // The last instruction might already
- // created a row for this offset and
- // we want to overwrite it.
- unwind_plan.InsertRow(
- std::make_shared<UnwindPlan::Row>(*m_curr_row),
- replace_existing);
- }
-
- // We are starting a new conditional block at the actual offset
- condition_block_start_offset = current_offset;
+ // If the last instruction was conditional with a different condition
+ // then the then current condition then restore the condition.
+ if (last_condition != EmulateInstruction::UnconditionalCondition) {
+ const auto &saved_state =
+ saved_unwind_states.at(condition_block_start_offset);
+ m_curr_row = std::make_shared<UnwindPlan::Row>(*saved_state.first);
+ m_curr_row->SetOffset(current_offset);
+ m_register_values = saved_state.second;
+ // re-set the CFA register ivars to match the new m_curr_row.
+ if (sp_reg_info.name &&
+ m_curr_row->GetCFAValue().IsRegisterPlusOffset()) {
+ uint32_t row_cfa_regnum =
+ m_curr_row->GetCFAValue().GetRegisterNumber();
+ lldb::RegisterKind row_kind =
+ m_unwind_plan_ptr->GetRegisterKind();
+ // set m_cfa_reg_info to the row's CFA reg.
+ m_cfa_reg_info = *m_inst_emulator_up->GetRegisterInfo(
+ row_kind, row_cfa_regnum);
+ // set m_fp_is_cfa.
+ if (sp_reg_info.kinds[row_kind] == row_cfa_regnum)
+ m_fp_is_cfa = false;
+ else
+ m_fp_is_cfa = true;
}
+ // The last instruction might already created a row for this offset
+ // and we want to overwrite it.
+ bool replace_existing = true;
+ unwind_plan.InsertRow(
+ std::make_shared<UnwindPlan::Row>(*m_curr_row),
+ replace_existing);
+ }
- if (log && log->GetVerbose()) {
- StreamString strm;
- lldb_private::FormatEntity::Entry format;
- FormatEntity::Parse("${frame.pc}: ", format);
- inst->Dump(&strm, inst_list.GetMaxOpcocdeByteSize(),
show_address,
- show_bytes, show_control_flow_kind, nullptr, nullptr,
- nullptr, &format, 0);
- log->PutString(strm.GetString());
- }
+ // We are starting a new conditional block at the actual offset
+ condition_block_start_offset = current_offset;
+ }
- last_condition = m_inst_emulator_up->GetInstructionCondition();
-
- m_inst_emulator_up->EvaluateInstruction(
- eEmulateInstructionOptionIgnoreConditions);
-
- // If the current instruction is a branch forward then save the
- // current CFI information for the offset where we are branching.
- if (m_forward_branch_offset != 0 &&
- range.ContainsFileAddress(inst->GetAddress().GetFileAddress() +
- m_forward_branch_offset)) {
- auto newrow =
- std::make_shared<UnwindPlan::Row>(*m_curr_row.get());
- newrow->SetOffset(current_offset + m_forward_branch_offset);
- saved_unwind_states.insert(
- {current_offset + m_forward_branch_offset,
- {newrow, m_register_values}});
- unwind_plan.InsertRow(newrow);
- }
+ if (log && log->GetVerbose()) {
+ StreamString strm;
+ lldb_private::FormatEntity::Entry format;
+ FormatEntity::Parse("${frame.pc}: ", format);
+ inst->Dump(&strm, inst_list.GetMaxOpcocdeByteSize(), show_address,
+ show_bytes, show_control_flow_kind, nullptr, nullptr,
+ nullptr, &format, 0);
+ log->PutString(strm.GetString());
+ }
- // Were there any changes to the CFI while evaluating this
- // instruction?
- if (m_curr_row_modified) {
- // Save the modified row if we don't already have a CFI row in
- // the current address
- if (saved_unwind_states.count(
- current_offset + inst->GetOpcode().GetByteSize()) == 0) {
- m_curr_row->SetOffset(current_offset +
- inst->GetOpcode().GetByteSize());
- unwind_plan.InsertRow(m_curr_row);
- saved_unwind_states.insert(
- {current_offset + inst->GetOpcode().GetByteSize(),
- {m_curr_row, m_register_values}});
-
- // Allocate a new Row for m_curr_row, copy the current state
- // into it
- UnwindPlan::Row *newrow = new UnwindPlan::Row;
- *newrow = *m_curr_row.get();
- m_curr_row.reset(newrow);
- }
- }
+ last_condition = m_inst_emulator_up->GetInstructionCondition();
+
+ m_inst_emulator_up->EvaluateInstruction(
+ eEmulateInstructionOptionIgnoreConditions);
+
+ // If the current instruction is a branch forward then save the current
+ // CFI information for the offset where we are branching.
+ if (m_forward_branch_offset != 0 &&
+ range.ContainsFileAddress(inst->GetAddress().GetFileAddress() +
+ m_forward_branch_offset)) {
+ auto newrow = std::make_shared<UnwindPlan::Row>(*m_curr_row.get());
+ newrow->SetOffset(current_offset + m_forward_branch_offset);
+ saved_unwind_states.insert({current_offset + m_forward_branch_offset,
+ {newrow, m_register_values}});
+ unwind_plan.InsertRow(newrow);
+ }
+
+ // Were there any changes to the CFI while evaluating this instruction?
+ if (m_curr_row_modified) {
+ // Save the modified row if we don't already have a CFI row in the
+ // current address
+ if (saved_unwind_states.count(current_offset +
+ inst->GetOpcode().GetByteSize()) == 0)
{
+ m_curr_row->SetOffset(current_offset +
+ inst->GetOpcode().GetByteSize());
+ unwind_plan.InsertRow(m_curr_row);
+ saved_unwind_states.insert(
+ {current_offset + inst->GetOpcode().GetByteSize(),
+ {m_curr_row, m_register_values}});
+
+ // Allocate a new Row for m_curr_row, copy the current state
+ // into it
+ UnwindPlan::Row *newrow = new UnwindPlan::Row;
+ *newrow = *m_curr_row.get();
+ m_curr_row.reset(newrow);
}
}
}
}
+ }
- if (log && log->GetVerbose()) {
- StreamString strm;
- lldb::addr_t base_addr = range.GetBaseAddress().GetFileAddress();
- strm.Printf("Resulting unwind rows for [0x%" PRIx64 " - 0x%" PRIx64 "):",
- base_addr, base_addr + range.GetByteSize());
- unwind_plan.Dump(strm, nullptr, base_addr);
- log->PutString(strm.GetString());
- }
- return unwind_plan.GetRowCount() > 0;
+ if (log && log->GetVerbose()) {
+ StreamString strm;
+ lldb::addr_t base_addr = range.GetBaseAddress().GetFileAddress();
+ strm.Printf("Resulting unwind rows for [0x%" PRIx64 " - 0x%" PRIx64 "):",
+ base_addr, base_addr + range.GetByteSize());
+ unwind_plan.Dump(strm, nullptr, base_addr);
+ log->PutString(strm.GetString());
}
- return false;
+ return unwind_plan.GetRowCount() > 0;
}
bool UnwindAssemblyInstEmulation::AugmentUnwindPlanFromCallSite(
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