[lldb][nfc] Reduce indentation in UnwindAssemblyInstruction (llvm#167914)

felipepiovezan · felipepiovezan · commit 1f93400f05e3 · 2025-11-14T16:24:45.000Z
diff --git a/lldb/source/Plugins/UnwindAssembly/InstEmulation/UnwindAssemblyInstEmulation.cpp b/lldb/source/Plugins/UnwindAssembly/InstEmulation/UnwindAssemblyInstEmulation.cpp
@@ -50,6 +50,18 @@ bool UnwindAssemblyInstEmulation::GetNonCallSiteUnwindPlanFromAssembly(
       range, function_text.data(), function_text.size(), unwind_plan);
 }
 
+static void DumpUnwindRowsToLog(Log *log, AddressRange range,
+                                const UnwindPlan &unwind_plan) {
+  if (!log || !log->GetVerbose())
+    return;
+  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());
+}
+
 bool UnwindAssemblyInstEmulation::GetNonCallSiteUnwindPlanFromAssembly(
     AddressRange &range, uint8_t *opcode_data, size_t opcode_size,
     UnwindPlan &unwind_plan) {
@@ -105,123 +117,118 @@ bool UnwindAssemblyInstEmulation::GetNonCallSiteUnwindPlanFromAssembly(
   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 state 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, UnwindState> saved_unwind_states;
-
-    // Make a copy of the current instruction Row and save it in m_state so
-    // we can add updates as we process the instructions.
-    m_state.row = *unwind_plan.GetLastRow();
-
-    // Add the initial state to the save list with offset 0.
-    auto condition_block_start_state =
-        saved_unwind_states.emplace(0, m_state).first;
-
-    // The architecture dependent condition code of the last processed
-    // instruction.
-    EmulateInstruction::InstructionCondition last_condition =
-        EmulateInstruction::UnconditionalCondition;
-
-    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)
-        continue;
-
-      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_state.row doesn't match with the offset we see in
-      // saved_unwind_states then we have to update current unwind state to
-      // the saved values. It is happening after we processed an epilogue and a
-      // return to caller instruction.
-      if (it->second.row.GetOffset() != m_state.row.GetOffset())
-        m_state = it->second;
-
-      m_inst_emulator_up->SetInstruction(inst->GetOpcode(), inst->GetAddress(),
-                                         nullptr);
-
-      if (last_condition != m_inst_emulator_up->GetInstructionCondition()) {
-        // If the last instruction was conditional with a different condition
-        // than the current condition then restore the state.
-        if (last_condition != EmulateInstruction::UnconditionalCondition) {
-          m_state = condition_block_start_state->second;
-          m_state.row.SetOffset(current_offset);
-          // The last instruction might already created a row for this offset
-          // and we want to overwrite it.
-          saved_unwind_states.insert_or_assign(current_offset, m_state);
-        }
+  if (num_instructions == 0) {
+    DumpUnwindRowsToLog(log, range, unwind_plan);
+    return unwind_plan.GetRowCount() > 0;
+  }
 
-        // We are starting a new conditional block at the actual offset
-        condition_block_start_state = it;
-      }
+  Instruction *inst = inst_list.GetInstructionAtIndex(0).get();
+  const lldb::addr_t base_addr = inst->GetAddress().GetFileAddress();
 
-      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());
-      }
+  // Map for storing the unwind state 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, UnwindState> saved_unwind_states;
 
-      last_condition = m_inst_emulator_up->GetInstructionCondition();
+  // Make a copy of the current instruction Row and save it in m_state so
+  // we can add updates as we process the instructions.
+  m_state.row = *unwind_plan.GetLastRow();
 
-      m_inst_emulator_up->EvaluateInstruction(
-          eEmulateInstructionOptionIgnoreConditions);
+  // Add the initial state to the save list with offset 0.
+  auto condition_block_start_state =
+      saved_unwind_states.emplace(0, m_state).first;
 
-      // 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)) {
-        if (auto [it, inserted] = saved_unwind_states.emplace(
-                current_offset + m_forward_branch_offset, m_state);
-            inserted)
-          it->second.row.SetOffset(current_offset + m_forward_branch_offset);
+  // The architecture dependent condition code of the last processed
+  // instruction.
+  EmulateInstruction::InstructionCondition last_condition =
+      EmulateInstruction::UnconditionalCondition;
+
+  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)
+      continue;
+
+    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_state.row doesn't match with the offset we see in
+    // saved_unwind_states then we have to update current unwind state to
+    // the saved values. It is happening after we processed an epilogue and a
+    // return to caller instruction.
+    if (it->second.row.GetOffset() != m_state.row.GetOffset())
+      m_state = it->second;
+
+    m_inst_emulator_up->SetInstruction(inst->GetOpcode(), inst->GetAddress(),
+                                       nullptr);
+
+    if (last_condition != m_inst_emulator_up->GetInstructionCondition()) {
+      // If the last instruction was conditional with a different condition
+      // than the current condition then restore the state.
+      if (last_condition != EmulateInstruction::UnconditionalCondition) {
+        m_state = condition_block_start_state->second;
+        m_state.row.SetOffset(current_offset);
+        // The last instruction might already created a row for this offset
+        // and we want to overwrite it.
+        saved_unwind_states.insert_or_assign(current_offset, m_state);
       }
 
-      // 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_state.row.SetOffset(current_offset +
-                                inst->GetOpcode().GetByteSize());
-          saved_unwind_states.emplace(
-              current_offset + inst->GetOpcode().GetByteSize(), m_state);
-        }
-      }
+      // We are starting a new conditional block at the actual offset
+      condition_block_start_state = it;
     }
-    for (auto &[_, state] : saved_unwind_states) {
-      unwind_plan.InsertRow(std::move(state.row),
-                            /*replace_existing=*/true);
+
+    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());
     }
-  }
 
-  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());
+    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)) {
+      if (auto [it, inserted] = saved_unwind_states.emplace(
+              current_offset + m_forward_branch_offset, m_state);
+          inserted)
+        it->second.row.SetOffset(current_offset + m_forward_branch_offset);
+    }
+
+    // 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_state.row.SetOffset(current_offset + inst->GetOpcode().GetByteSize());
+        saved_unwind_states.emplace(
+            current_offset + inst->GetOpcode().GetByteSize(), m_state);
+      }
+    }
   }
+
+  for (auto &[_, state] : saved_unwind_states)
+    unwind_plan.InsertRow(std::move(state.row),
+                          /*replace_existing=*/true);
+
+  DumpUnwindRowsToLog(log, range, unwind_plan);
   return unwind_plan.GetRowCount() > 0;
 }
 
