[Lldb-commits] [lldb] RISCV unwinding enable (PR #158161)

[David Peixotto via lldb-commits]

================
@@ -1745,6 +1831,61 @@ EmulateInstructionRISCV::GetRegisterInfo(RegisterKind reg_kind,
   return array[reg_index];
 }
 
+bool EmulateInstructionRISCV::SetInstruction(const Opcode &opcode,
+                                             const Address &inst_addr,
+                                             Target *target) {
+  // Call the base class implementation
+  if (!EmulateInstruction::SetInstruction(opcode, inst_addr, target))
+    return false;
+
+  // Extract instruction data from the opcode
+  uint32_t inst_data = 0;
+  const void *opcode_data = m_opcode.GetOpcodeBytes();
+  if (!opcode_data)
+    return false;
+
+  if (m_opcode.GetByteSize() == 2) {
+    // 16-bit compressed instruction
+    const uint16_t *data = static_cast<const uint16_t *>(opcode_data);
+    inst_data = *data;
+  } else if (m_opcode.GetByteSize() == 4) {
+    // 32-bit instruction
+    const uint32_t *data = static_cast<const uint32_t *>(opcode_data);
+    inst_data = *data;
+  } else {
+    return false;
+  }
+
+  // Decode the instruction
+  auto decoded_inst = Decode(inst_data);
+  if (!decoded_inst)
+    return false;
+
+  // Store the decoded result
+  m_decoded = *decoded_inst;
+  return true;
+}
+
+bool EmulateInstructionRISCV::CreateFunctionEntryUnwind(
+    UnwindPlan &unwind_plan) {
+  unwind_plan.Clear();
+  unwind_plan.SetRegisterKind(eRegisterKindLLDB);
+
+  UnwindPlan::Row row;
+
+  row.GetCFAValue().SetIsRegisterPlusOffset(gpr_sp_riscv, 0);
+  row.SetRegisterLocationToSame(gpr_ra_riscv, /*must_replace=*/false);
+  row.SetRegisterLocationToSame(gpr_fp_riscv, /*must_replace=*/false);
+
+  unwind_plan.AppendRow(std::move(row));
+  unwind_plan.SetSourceName("EmulateInstructionRISCV");
+  unwind_plan.SetSourcedFromCompiler(eLazyBoolNo);
+  unwind_plan.SetUnwindPlanValidAtAllInstructions(eLazyBoolYes);
----------------
dmpots wrote:

Is this unwind plan truly valid at all instructions?

https://github.com/llvm/llvm-project/pull/158161