| // Copyright 2016 the V8 project authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #include "src/compiler/arm64/unwinding-info-writer-arm64.h" |
| #include "src/compiler/instruction.h" |
| |
| namespace v8 { |
| namespace internal { |
| namespace compiler { |
| |
| void UnwindingInfoWriter::BeginInstructionBlock(int pc_offset, |
| const InstructionBlock* block) { |
| if (!enabled()) return; |
| |
| block_will_exit_ = false; |
| |
| DCHECK_LT(block->rpo_number().ToInt(), |
| static_cast<int>(block_initial_states_.size())); |
| const BlockInitialState* initial_state = |
| block_initial_states_[block->rpo_number().ToInt()]; |
| if (initial_state) { |
| if (initial_state->saved_lr_ != saved_lr_) { |
| eh_frame_writer_.AdvanceLocation(pc_offset); |
| if (initial_state->saved_lr_) { |
| eh_frame_writer_.RecordRegisterSavedToStack(lr, kPointerSize); |
| eh_frame_writer_.RecordRegisterSavedToStack(fp, 0); |
| } else { |
| eh_frame_writer_.RecordRegisterFollowsInitialRule(lr); |
| } |
| saved_lr_ = initial_state->saved_lr_; |
| } |
| } else { |
| // The entry block always lacks an explicit initial state. |
| // The exit block may lack an explicit state, if it is only reached by |
| // the block ending in a ret. |
| // All the other blocks must have an explicit initial state. |
| DCHECK(block->predecessors().empty() || block->successors().empty()); |
| } |
| } |
| |
| void UnwindingInfoWriter::EndInstructionBlock(const InstructionBlock* block) { |
| if (!enabled() || block_will_exit_) return; |
| |
| for (const RpoNumber& successor : block->successors()) { |
| int successor_index = successor.ToInt(); |
| DCHECK_LT(successor_index, static_cast<int>(block_initial_states_.size())); |
| const BlockInitialState* existing_state = |
| block_initial_states_[successor_index]; |
| |
| // If we already had an entry for this BB, check that the values are the |
| // same we are trying to insert. |
| if (existing_state) { |
| DCHECK_EQ(existing_state->saved_lr_, saved_lr_); |
| } else { |
| block_initial_states_[successor_index] = |
| new (zone_) BlockInitialState(saved_lr_); |
| } |
| } |
| } |
| |
| void UnwindingInfoWriter::MarkFrameConstructed(int at_pc) { |
| if (!enabled()) return; |
| |
| // Regardless of the type of frame constructed, the relevant part of the |
| // layout is always the one in the diagram: |
| // |
| // | .... | higher addresses |
| // +----------+ ^ |
| // | LR | | | |
| // +----------+ | | |
| // | saved FP | | | |
| // +----------+ <-- FP v |
| // | .... | stack growth |
| // |
| // The LR is pushed on the stack, and we can record this fact at the end of |
| // the construction, since the LR itself is not modified in the process. |
| eh_frame_writer_.AdvanceLocation(at_pc); |
| eh_frame_writer_.RecordRegisterSavedToStack(lr, kPointerSize); |
| eh_frame_writer_.RecordRegisterSavedToStack(fp, 0); |
| saved_lr_ = true; |
| } |
| |
| void UnwindingInfoWriter::MarkFrameDeconstructed(int at_pc) { |
| if (!enabled()) return; |
| |
| // The lr is restored by the last operation in LeaveFrame(). |
| eh_frame_writer_.AdvanceLocation(at_pc); |
| eh_frame_writer_.RecordRegisterFollowsInitialRule(lr); |
| saved_lr_ = false; |
| } |
| |
| void UnwindingInfoWriter::MarkLinkRegisterOnTopOfStack(int pc_offset, |
| const Register& sp) { |
| if (!enabled()) return; |
| |
| eh_frame_writer_.AdvanceLocation(pc_offset); |
| eh_frame_writer_.SetBaseAddressRegisterAndOffset(sp, 0); |
| eh_frame_writer_.RecordRegisterSavedToStack(lr, 0); |
| } |
| |
| void UnwindingInfoWriter::MarkPopLinkRegisterFromTopOfStack(int pc_offset) { |
| if (!enabled()) return; |
| |
| eh_frame_writer_.AdvanceLocation(pc_offset); |
| eh_frame_writer_.SetBaseAddressRegisterAndOffset(fp, 0); |
| eh_frame_writer_.RecordRegisterFollowsInitialRule(lr); |
| } |
| |
| } // namespace compiler |
| } // namespace internal |
| } // namespace v8 |