bool DWARFCallFrameInfo::FDEToUnwindPlan (dw_offset_t offset, Address startaddr, UnwindPlan& unwind_plan) { dw_offset_t current_entry = offset; if (m_section_sp.get() == NULL || m_section_sp->IsEncrypted()) return false; if (m_cfi_data_initialized == false) GetCFIData(); uint32_t length = m_cfi_data.GetU32 (&offset); dw_offset_t cie_offset = m_cfi_data.GetU32 (&offset); assert (cie_offset != 0 && cie_offset != UINT32_MAX); // Translate the CIE_id from the eh_frame format, which // is relative to the FDE offset, into a __eh_frame section // offset if (m_is_eh_frame) { unwind_plan.SetSourceName ("eh_frame CFI"); cie_offset = current_entry + 4 - cie_offset; unwind_plan.SetUnwindPlanValidAtAllInstructions (eLazyBoolNo); } else { unwind_plan.SetSourceName ("DWARF CFI"); // In theory the debug_frame info should be valid at all call sites // ("asynchronous unwind info" as it is sometimes called) but in practice // gcc et al all emit call frame info for the prologue and call sites, but // not for the epilogue or all the other locations during the function reliably. unwind_plan.SetUnwindPlanValidAtAllInstructions (eLazyBoolNo); } unwind_plan.SetSourcedFromCompiler (eLazyBoolYes); const CIE *cie = GetCIE (cie_offset); assert (cie != NULL); const dw_offset_t end_offset = current_entry + length + 4; const lldb::addr_t pc_rel_addr = m_section_sp->GetFileAddress(); const lldb::addr_t text_addr = LLDB_INVALID_ADDRESS; const lldb::addr_t data_addr = LLDB_INVALID_ADDRESS; lldb::addr_t range_base = m_cfi_data.GetGNUEHPointer(&offset, cie->ptr_encoding, pc_rel_addr, text_addr, data_addr); lldb::addr_t range_len = m_cfi_data.GetGNUEHPointer(&offset, cie->ptr_encoding & DW_EH_PE_MASK_ENCODING, pc_rel_addr, text_addr, data_addr); AddressRange range (range_base, m_objfile.GetAddressByteSize(), m_objfile.GetSectionList()); range.SetByteSize (range_len); if (cie->augmentation[0] == 'z') { uint32_t aug_data_len = (uint32_t)m_cfi_data.GetULEB128(&offset); offset += aug_data_len; } uint32_t reg_num = 0; int32_t op_offset = 0; uint32_t code_align = cie->code_align; int32_t data_align = cie->data_align; unwind_plan.SetPlanValidAddressRange (range); UnwindPlan::Row *cie_initial_row = new UnwindPlan::Row; *cie_initial_row = cie->initial_row; UnwindPlan::RowSP row(cie_initial_row); unwind_plan.SetRegisterKind (m_reg_kind); unwind_plan.SetReturnAddressRegister (cie->return_addr_reg_num); UnwindPlan::Row::RegisterLocation reg_location; while (m_cfi_data.ValidOffset(offset) && offset < end_offset) { uint8_t inst = m_cfi_data.GetU8(&offset); uint8_t primary_opcode = inst & 0xC0; uint8_t extended_opcode = inst & 0x3F; if (primary_opcode) { switch (primary_opcode) { case DW_CFA_advance_loc : // (Row Creation Instruction) { // 0x40 - high 2 bits are 0x1, lower 6 bits are delta // takes a single argument that represents a constant delta. The // required action is to create a new table row with a location // value that is computed by taking the current entry's location // value and adding (delta * code_align). All other // values in the new row are initially identical to the current row. unwind_plan.AppendRow(row); UnwindPlan::Row *newrow = new UnwindPlan::Row; *newrow = *row.get(); row.reset (newrow); row->SlideOffset(extended_opcode * code_align); } break; case DW_CFA_offset : { // 0x80 - high 2 bits are 0x2, lower 6 bits are register // takes two arguments: an unsigned LEB128 constant representing a // factored offset and a register number. The required action is to // change the rule for the register indicated by the register number // to be an offset(N) rule with a value of // (N = factored offset * data_align). reg_num = extended_opcode; op_offset = (int32_t)m_cfi_data.GetULEB128(&offset) * data_align; reg_location.SetAtCFAPlusOffset(op_offset); row->SetRegisterInfo (reg_num, reg_location); } break; case DW_CFA_restore : { // 0xC0 - high 2 bits are 0x3, lower 6 bits are register // takes a single argument that represents a register number. The // required action is to change the rule for the indicated register // to the rule assigned it by the initial_instructions in the CIE. reg_num = extended_opcode; // We only keep enough register locations around to // unwind what is in our thread, and these are organized // by the register index in that state, so we need to convert our // GCC register number from the EH frame info, to a register index if (unwind_plan.IsValidRowIndex(0) && unwind_plan.GetRowAtIndex(0)->GetRegisterInfo(reg_num, reg_location)) row->SetRegisterInfo (reg_num, reg_location); } break; } } else { switch (extended_opcode) { case DW_CFA_nop : // 0x0 break; case DW_CFA_set_loc : // 0x1 (Row Creation Instruction) { // DW_CFA_set_loc takes a single argument that represents an address. // The required action is to create a new table row using the // specified address as the location. All other values in the new row // are initially identical to the current row. The new location value // should always be greater than the current one. unwind_plan.AppendRow(row); UnwindPlan::Row *newrow = new UnwindPlan::Row; *newrow = *row.get(); row.reset (newrow); row->SetOffset(m_cfi_data.GetPointer(&offset) - startaddr.GetFileAddress()); } break; case DW_CFA_advance_loc1 : // 0x2 (Row Creation Instruction) { // takes a single uword argument that represents a constant delta. // This instruction is identical to DW_CFA_advance_loc except for the // encoding and size of the delta argument. unwind_plan.AppendRow(row); UnwindPlan::Row *newrow = new UnwindPlan::Row; *newrow = *row.get(); row.reset (newrow); row->SlideOffset (m_cfi_data.GetU8(&offset) * code_align); } break; case DW_CFA_advance_loc2 : // 0x3 (Row Creation Instruction) { // takes a single uword argument that represents a constant delta. // This instruction is identical to DW_CFA_advance_loc except for the // encoding and size of the delta argument. unwind_plan.AppendRow(row); UnwindPlan::Row *newrow = new UnwindPlan::Row; *newrow = *row.get(); row.reset (newrow); row->SlideOffset (m_cfi_data.GetU16(&offset) * code_align); } break; case DW_CFA_advance_loc4 : // 0x4 (Row Creation Instruction) { // takes a single uword argument that represents a constant delta. // This instruction is identical to DW_CFA_advance_loc except for the // encoding and size of the delta argument. unwind_plan.AppendRow(row); UnwindPlan::Row *newrow = new UnwindPlan::Row; *newrow = *row.get(); row.reset (newrow); row->SlideOffset (m_cfi_data.GetU32(&offset) * code_align); } break; case DW_CFA_offset_extended : // 0x5 { // takes two unsigned LEB128 arguments representing a register number // and a factored offset. This instruction is identical to DW_CFA_offset // except for the encoding and size of the register argument. reg_num = (uint32_t)m_cfi_data.GetULEB128(&offset); op_offset = (int32_t)m_cfi_data.GetULEB128(&offset) * data_align; reg_location.SetAtCFAPlusOffset(op_offset); row->SetRegisterInfo (reg_num, reg_location); } break; case DW_CFA_restore_extended : // 0x6 { // takes a single unsigned LEB128 argument that represents a register // number. This instruction is identical to DW_CFA_restore except for // the encoding and size of the register argument. reg_num = (uint32_t)m_cfi_data.GetULEB128(&offset); if (unwind_plan.IsValidRowIndex(0) && unwind_plan.GetRowAtIndex(0)->GetRegisterInfo(reg_num, reg_location)) row->SetRegisterInfo (reg_num, reg_location); } break; case DW_CFA_undefined : // 0x7 { // takes a single unsigned LEB128 argument that represents a register // number. The required action is to set the rule for the specified // register to undefined. reg_num = (uint32_t)m_cfi_data.GetULEB128(&offset); reg_location.SetUndefined(); row->SetRegisterInfo (reg_num, reg_location); } break; case DW_CFA_same_value : // 0x8 { // takes a single unsigned LEB128 argument that represents a register // number. The required action is to set the rule for the specified // register to same value. reg_num = (uint32_t)m_cfi_data.GetULEB128(&offset); reg_location.SetSame(); row->SetRegisterInfo (reg_num, reg_location); } break; case DW_CFA_register : // 0x9 { // takes two unsigned LEB128 arguments representing register numbers. // The required action is to set the rule for the first register to be // the second register. reg_num = (uint32_t)m_cfi_data.GetULEB128(&offset); uint32_t other_reg_num = (uint32_t)m_cfi_data.GetULEB128(&offset); reg_location.SetInRegister(other_reg_num); row->SetRegisterInfo (reg_num, reg_location); } break; case DW_CFA_remember_state : // 0xA { // These instructions define a stack of information. Encountering the // DW_CFA_remember_state instruction means to save the rules for every // register on the current row on the stack. Encountering the // DW_CFA_restore_state instruction means to pop the set of rules off // the stack and place them in the current row. (This operation is // useful for compilers that move epilogue code into the body of a // function.) unwind_plan.AppendRow (row); UnwindPlan::Row *newrow = new UnwindPlan::Row; *newrow = *row.get(); row.reset (newrow); } break; case DW_CFA_restore_state : // 0xB // These instructions define a stack of information. Encountering the // DW_CFA_remember_state instruction means to save the rules for every // register on the current row on the stack. Encountering the // DW_CFA_restore_state instruction means to pop the set of rules off // the stack and place them in the current row. (This operation is // useful for compilers that move epilogue code into the body of a // function.) { row = unwind_plan.GetRowAtIndex(unwind_plan.GetRowCount() - 1); } break; case DW_CFA_def_cfa : // 0xC (CFA Definition Instruction) { // Takes two unsigned LEB128 operands representing a register // number and a (non-factored) offset. The required action // is to define the current CFA rule to use the provided // register and offset. reg_num = (uint32_t)m_cfi_data.GetULEB128(&offset); op_offset = (int32_t)m_cfi_data.GetULEB128(&offset); row->SetCFARegister (reg_num); row->SetCFAOffset (op_offset); } break; case DW_CFA_def_cfa_register : // 0xD (CFA Definition Instruction) { // takes a single unsigned LEB128 argument representing a register // number. The required action is to define the current CFA rule to // use the provided register (but to keep the old offset). reg_num = (uint32_t)m_cfi_data.GetULEB128(&offset); row->SetCFARegister (reg_num); } break; case DW_CFA_def_cfa_offset : // 0xE (CFA Definition Instruction) { // Takes a single unsigned LEB128 operand representing a // (non-factored) offset. The required action is to define // the current CFA rule to use the provided offset (but // to keep the old register). op_offset = (int32_t)m_cfi_data.GetULEB128(&offset); row->SetCFAOffset (op_offset); } break; case DW_CFA_def_cfa_expression : // 0xF (CFA Definition Instruction) { size_t block_len = (size_t)m_cfi_data.GetULEB128(&offset); offset += (uint32_t)block_len; } break; case DW_CFA_expression : // 0x10 { // Takes two operands: an unsigned LEB128 value representing // a register number, and a DW_FORM_block value representing a DWARF // expression. The required action is to change the rule for the // register indicated by the register number to be an expression(E) // rule where E is the DWARF expression. That is, the DWARF // expression computes the address. The value of the CFA is // pushed on the DWARF evaluation stack prior to execution of // the DWARF expression. reg_num = (uint32_t)m_cfi_data.GetULEB128(&offset); uint32_t block_len = (uint32_t)m_cfi_data.GetULEB128(&offset); const uint8_t *block_data = (uint8_t *)m_cfi_data.GetData(&offset, block_len); reg_location.SetAtDWARFExpression(block_data, block_len); row->SetRegisterInfo (reg_num, reg_location); } break; case DW_CFA_offset_extended_sf : // 0x11 { // takes two operands: an unsigned LEB128 value representing a // register number and a signed LEB128 factored offset. This // instruction is identical to DW_CFA_offset_extended except //that the second operand is signed and factored. reg_num = (uint32_t)m_cfi_data.GetULEB128(&offset); op_offset = (int32_t)m_cfi_data.GetSLEB128(&offset) * data_align; reg_location.SetAtCFAPlusOffset(op_offset); row->SetRegisterInfo (reg_num, reg_location); } break; case DW_CFA_def_cfa_sf : // 0x12 (CFA Definition Instruction) { // Takes two operands: an unsigned LEB128 value representing // a register number and a signed LEB128 factored offset. // This instruction is identical to DW_CFA_def_cfa except // that the second operand is signed and factored. reg_num = (uint32_t)m_cfi_data.GetULEB128(&offset); op_offset = (int32_t)m_cfi_data.GetSLEB128(&offset) * data_align; row->SetCFARegister (reg_num); row->SetCFAOffset (op_offset); } break; case DW_CFA_def_cfa_offset_sf : // 0x13 (CFA Definition Instruction) { // takes a signed LEB128 operand representing a factored // offset. This instruction is identical to DW_CFA_def_cfa_offset // except that the operand is signed and factored. op_offset = (int32_t)m_cfi_data.GetSLEB128(&offset) * data_align; row->SetCFAOffset (op_offset); } break; case DW_CFA_val_expression : // 0x16 { // takes two operands: an unsigned LEB128 value representing a register // number, and a DW_FORM_block value representing a DWARF expression. // The required action is to change the rule for the register indicated // by the register number to be a val_expression(E) rule where E is the // DWARF expression. That is, the DWARF expression computes the value of // the given register. The value of the CFA is pushed on the DWARF // evaluation stack prior to execution of the DWARF expression. reg_num = (uint32_t)m_cfi_data.GetULEB128(&offset); uint32_t block_len = (uint32_t)m_cfi_data.GetULEB128(&offset); const uint8_t* block_data = (uint8_t*)m_cfi_data.GetData(&offset, block_len); //#if defined(__i386__) || defined(__x86_64__) // // The EH frame info for EIP and RIP contains code that looks for traps to // // be a specific type and increments the PC. // // For i386: // // DW_CFA_val_expression where: // // eip = DW_OP_breg6(+28), DW_OP_deref, DW_OP_dup, DW_OP_plus_uconst(0x34), // // DW_OP_deref, DW_OP_swap, DW_OP_plus_uconst(0), DW_OP_deref, // // DW_OP_dup, DW_OP_lit3, DW_OP_ne, DW_OP_swap, DW_OP_lit4, DW_OP_ne, // // DW_OP_and, DW_OP_plus // // This basically does a: // // eip = ucontenxt.mcontext32->gpr.eip; // // if (ucontenxt.mcontext32->exc.trapno != 3 && ucontenxt.mcontext32->exc.trapno != 4) // // eip++; // // // // For x86_64: // // DW_CFA_val_expression where: // // rip = DW_OP_breg3(+48), DW_OP_deref, DW_OP_dup, DW_OP_plus_uconst(0x90), DW_OP_deref, // // DW_OP_swap, DW_OP_plus_uconst(0), DW_OP_deref_size(4), DW_OP_dup, DW_OP_lit3, // // DW_OP_ne, DW_OP_swap, DW_OP_lit4, DW_OP_ne, DW_OP_and, DW_OP_plus // // This basically does a: // // rip = ucontenxt.mcontext64->gpr.rip; // // if (ucontenxt.mcontext64->exc.trapno != 3 && ucontenxt.mcontext64->exc.trapno != 4) // // rip++; // // The trap comparisons and increments are not needed as it hoses up the unwound PC which // // is expected to point at least past the instruction that causes the fault/trap. So we // // take it out by trimming the expression right at the first "DW_OP_swap" opcodes // if (block_data != NULL && thread->GetPCRegNum(Thread::GCC) == reg_num) // { // if (thread->Is64Bit()) // { // if (block_len > 9 && block_data[8] == DW_OP_swap && block_data[9] == DW_OP_plus_uconst) // block_len = 8; // } // else // { // if (block_len > 8 && block_data[7] == DW_OP_swap && block_data[8] == DW_OP_plus_uconst) // block_len = 7; // } // } //#endif reg_location.SetIsDWARFExpression(block_data, block_len); row->SetRegisterInfo (reg_num, reg_location); } break; case DW_CFA_val_offset : // 0x14 case DW_CFA_val_offset_sf : // 0x15 default: break; } } } unwind_plan.AppendRow(row); return true; }
bool DWARFCallFrameInfo::FDEToUnwindPlan (dw_offset_t dwarf_offset, Address startaddr, UnwindPlan& unwind_plan) { lldb::offset_t offset = dwarf_offset; lldb::offset_t current_entry = offset; if (m_section_sp.get() == nullptr || m_section_sp->IsEncrypted()) return false; if (m_cfi_data_initialized == false) GetCFIData(); uint32_t length = m_cfi_data.GetU32 (&offset); dw_offset_t cie_offset; bool is_64bit = (length == UINT32_MAX); if (is_64bit) { length = m_cfi_data.GetU64 (&offset); cie_offset = m_cfi_data.GetU64 (&offset); } else { cie_offset = m_cfi_data.GetU32 (&offset); } assert (cie_offset != 0 && cie_offset != UINT32_MAX); // Translate the CIE_id from the eh_frame format, which // is relative to the FDE offset, into a __eh_frame section // offset if (m_is_eh_frame) { unwind_plan.SetSourceName ("eh_frame CFI"); cie_offset = current_entry + (is_64bit ? 12 : 4) - cie_offset; unwind_plan.SetUnwindPlanValidAtAllInstructions (eLazyBoolNo); } else { unwind_plan.SetSourceName ("DWARF CFI"); // In theory the debug_frame info should be valid at all call sites // ("asynchronous unwind info" as it is sometimes called) but in practice // gcc et al all emit call frame info for the prologue and call sites, but // not for the epilogue or all the other locations during the function reliably. unwind_plan.SetUnwindPlanValidAtAllInstructions (eLazyBoolNo); } unwind_plan.SetSourcedFromCompiler (eLazyBoolYes); const CIE *cie = GetCIE (cie_offset); assert (cie != nullptr); const dw_offset_t end_offset = current_entry + length + (is_64bit ? 12 : 4); const lldb::addr_t pc_rel_addr = m_section_sp->GetFileAddress(); const lldb::addr_t text_addr = LLDB_INVALID_ADDRESS; const lldb::addr_t data_addr = LLDB_INVALID_ADDRESS; lldb::addr_t range_base = m_cfi_data.GetGNUEHPointer(&offset, cie->ptr_encoding, pc_rel_addr, text_addr, data_addr); lldb::addr_t range_len = m_cfi_data.GetGNUEHPointer(&offset, cie->ptr_encoding & DW_EH_PE_MASK_ENCODING, pc_rel_addr, text_addr, data_addr); AddressRange range (range_base, m_objfile.GetAddressByteSize(), m_objfile.GetSectionList()); range.SetByteSize (range_len); addr_t lsda_data_file_address = LLDB_INVALID_ADDRESS; if (cie->augmentation[0] == 'z') { uint32_t aug_data_len = (uint32_t)m_cfi_data.GetULEB128(&offset); if (aug_data_len != 0 && cie->lsda_addr_encoding != DW_EH_PE_omit) { offset_t saved_offset = offset; lsda_data_file_address = m_cfi_data.GetGNUEHPointer(&offset, cie->lsda_addr_encoding, pc_rel_addr, text_addr, data_addr); if (offset - saved_offset != aug_data_len) { // There is more in the augmentation region than we know how to process; // don't read anything. lsda_data_file_address = LLDB_INVALID_ADDRESS; } offset = saved_offset; } offset += aug_data_len; } Address lsda_data; Address personality_function_ptr; if (lsda_data_file_address != LLDB_INVALID_ADDRESS && cie->personality_loc != LLDB_INVALID_ADDRESS) { m_objfile.GetModule()->ResolveFileAddress (lsda_data_file_address, lsda_data); m_objfile.GetModule()->ResolveFileAddress (cie->personality_loc, personality_function_ptr); } if (lsda_data.IsValid() && personality_function_ptr.IsValid()) { unwind_plan.SetLSDAAddress (lsda_data); unwind_plan.SetPersonalityFunctionPtr (personality_function_ptr); } uint32_t code_align = cie->code_align; int32_t data_align = cie->data_align; unwind_plan.SetPlanValidAddressRange (range); UnwindPlan::Row *cie_initial_row = new UnwindPlan::Row; *cie_initial_row = cie->initial_row; UnwindPlan::RowSP row(cie_initial_row); unwind_plan.SetRegisterKind (m_reg_kind); unwind_plan.SetReturnAddressRegister (cie->return_addr_reg_num); std::vector<UnwindPlan::RowSP> stack; UnwindPlan::Row::RegisterLocation reg_location; while (m_cfi_data.ValidOffset(offset) && offset < end_offset) { uint8_t inst = m_cfi_data.GetU8(&offset); uint8_t primary_opcode = inst & 0xC0; uint8_t extended_opcode = inst & 0x3F; if (!HandleCommonDwarfOpcode(primary_opcode, extended_opcode, data_align, offset, *row)) { if (primary_opcode) { switch (primary_opcode) { case DW_CFA_advance_loc : // (Row Creation Instruction) { // 0x40 - high 2 bits are 0x1, lower 6 bits are delta // takes a single argument that represents a constant delta. The // required action is to create a new table row with a location // value that is computed by taking the current entry's location // value and adding (delta * code_align). All other // values in the new row are initially identical to the current row. unwind_plan.AppendRow(row); UnwindPlan::Row *newrow = new UnwindPlan::Row; *newrow = *row.get(); row.reset (newrow); row->SlideOffset(extended_opcode * code_align); break; } case DW_CFA_restore : { // 0xC0 - high 2 bits are 0x3, lower 6 bits are register // takes a single argument that represents a register number. The // required action is to change the rule for the indicated register // to the rule assigned it by the initial_instructions in the CIE. uint32_t reg_num = extended_opcode; // We only keep enough register locations around to // unwind what is in our thread, and these are organized // by the register index in that state, so we need to convert our // GCC register number from the EH frame info, to a register index if (unwind_plan.IsValidRowIndex(0) && unwind_plan.GetRowAtIndex(0)->GetRegisterInfo(reg_num, reg_location)) row->SetRegisterInfo (reg_num, reg_location); break; } } } else { switch (extended_opcode) { case DW_CFA_set_loc : // 0x1 (Row Creation Instruction) { // DW_CFA_set_loc takes a single argument that represents an address. // The required action is to create a new table row using the // specified address as the location. All other values in the new row // are initially identical to the current row. The new location value // should always be greater than the current one. unwind_plan.AppendRow(row); UnwindPlan::Row *newrow = new UnwindPlan::Row; *newrow = *row.get(); row.reset (newrow); row->SetOffset(m_cfi_data.GetPointer(&offset) - startaddr.GetFileAddress()); break; } case DW_CFA_advance_loc1 : // 0x2 (Row Creation Instruction) { // takes a single uword argument that represents a constant delta. // This instruction is identical to DW_CFA_advance_loc except for the // encoding and size of the delta argument. unwind_plan.AppendRow(row); UnwindPlan::Row *newrow = new UnwindPlan::Row; *newrow = *row.get(); row.reset (newrow); row->SlideOffset (m_cfi_data.GetU8(&offset) * code_align); break; } case DW_CFA_advance_loc2 : // 0x3 (Row Creation Instruction) { // takes a single uword argument that represents a constant delta. // This instruction is identical to DW_CFA_advance_loc except for the // encoding and size of the delta argument. unwind_plan.AppendRow(row); UnwindPlan::Row *newrow = new UnwindPlan::Row; *newrow = *row.get(); row.reset (newrow); row->SlideOffset (m_cfi_data.GetU16(&offset) * code_align); break; } case DW_CFA_advance_loc4 : // 0x4 (Row Creation Instruction) { // takes a single uword argument that represents a constant delta. // This instruction is identical to DW_CFA_advance_loc except for the // encoding and size of the delta argument. unwind_plan.AppendRow(row); UnwindPlan::Row *newrow = new UnwindPlan::Row; *newrow = *row.get(); row.reset (newrow); row->SlideOffset (m_cfi_data.GetU32(&offset) * code_align); break; } case DW_CFA_restore_extended : // 0x6 { // takes a single unsigned LEB128 argument that represents a register // number. This instruction is identical to DW_CFA_restore except for // the encoding and size of the register argument. uint32_t reg_num = (uint32_t)m_cfi_data.GetULEB128(&offset); if (unwind_plan.IsValidRowIndex(0) && unwind_plan.GetRowAtIndex(0)->GetRegisterInfo(reg_num, reg_location)) row->SetRegisterInfo (reg_num, reg_location); break; } case DW_CFA_remember_state : // 0xA { // These instructions define a stack of information. Encountering the // DW_CFA_remember_state instruction means to save the rules for every // register on the current row on the stack. Encountering the // DW_CFA_restore_state instruction means to pop the set of rules off // the stack and place them in the current row. (This operation is // useful for compilers that move epilogue code into the body of a // function.) stack.push_back (row); UnwindPlan::Row *newrow = new UnwindPlan::Row; *newrow = *row.get(); row.reset (newrow); break; } case DW_CFA_restore_state : // 0xB { // These instructions define a stack of information. Encountering the // DW_CFA_remember_state instruction means to save the rules for every // register on the current row on the stack. Encountering the // DW_CFA_restore_state instruction means to pop the set of rules off // the stack and place them in the current row. (This operation is // useful for compilers that move epilogue code into the body of a // function.) lldb::addr_t offset = row->GetOffset (); row = stack.back (); stack.pop_back (); row->SetOffset (offset); break; } case DW_CFA_val_offset : // 0x14 case DW_CFA_val_offset_sf : // 0x15 default: break; } } } } unwind_plan.AppendRow(row); return true; }