| // Copyright 2011 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/disassembler.h" |
| |
| #include <memory> |
| #include <vector> |
| |
| #include "src/assembler-inl.h" |
| #include "src/code-reference.h" |
| #include "src/code-stubs.h" |
| #include "src/debug/debug.h" |
| #include "src/deoptimizer.h" |
| #include "src/disasm.h" |
| #include "src/ic/ic.h" |
| #include "src/instruction-stream.h" |
| #include "src/macro-assembler.h" |
| #include "src/objects-inl.h" |
| #include "src/snapshot/serializer-common.h" |
| #include "src/string-stream.h" |
| #include "src/wasm/wasm-code-manager.h" |
| #include "src/wasm/wasm-engine.h" |
| |
| namespace v8 { |
| namespace internal { |
| |
| #ifdef ENABLE_DISASSEMBLER |
| |
| class V8NameConverter: public disasm::NameConverter { |
| public: |
| explicit V8NameConverter(Isolate* isolate, CodeReference code = {}) |
| : isolate_(isolate), code_(code) {} |
| const char* NameOfAddress(byte* pc) const override; |
| const char* NameInCode(byte* addr) const override; |
| const char* RootRelativeName(int offset) const override; |
| |
| const CodeReference& code() const { return code_; } |
| |
| private: |
| Isolate* isolate_; |
| CodeReference code_; |
| |
| EmbeddedVector<char, 128> v8_buffer_; |
| }; |
| |
| |
| const char* V8NameConverter::NameOfAddress(byte* pc) const { |
| if (!code_.is_null()) { |
| const char* name = |
| isolate_ ? isolate_->builtins()->Lookup(reinterpret_cast<Address>(pc)) |
| : nullptr; |
| |
| if (name != nullptr) { |
| SNPrintF(v8_buffer_, "%p (%s)", static_cast<void*>(pc), name); |
| return v8_buffer_.start(); |
| } |
| |
| int offs = static_cast<int>(reinterpret_cast<Address>(pc) - |
| code_.instruction_start()); |
| // print as code offset, if it seems reasonable |
| if (0 <= offs && offs < code_.instruction_size()) { |
| SNPrintF(v8_buffer_, "%p <+0x%x>", static_cast<void*>(pc), offs); |
| return v8_buffer_.start(); |
| } |
| |
| wasm::WasmCode* wasm_code = |
| isolate_ ? isolate_->wasm_engine()->code_manager()->LookupCode( |
| reinterpret_cast<Address>(pc)) |
| : nullptr; |
| if (wasm_code != nullptr) { |
| SNPrintF(v8_buffer_, "%p (%s)", static_cast<void*>(pc), |
| wasm::GetWasmCodeKindAsString(wasm_code->kind())); |
| return v8_buffer_.start(); |
| } |
| } |
| |
| return disasm::NameConverter::NameOfAddress(pc); |
| } |
| |
| |
| const char* V8NameConverter::NameInCode(byte* addr) const { |
| // The V8NameConverter is used for well known code, so we can "safely" |
| // dereference pointers in generated code. |
| return code_.is_null() ? "" : reinterpret_cast<const char*>(addr); |
| } |
| |
| const char* V8NameConverter::RootRelativeName(int offset) const { |
| if (isolate_ == nullptr) return nullptr; |
| |
| const int kRootsStart = 0; |
| const int kRootsEnd = Heap::roots_to_external_reference_table_offset(); |
| const int kExtRefsStart = Heap::roots_to_external_reference_table_offset(); |
| const int kExtRefsEnd = Heap::roots_to_builtins_offset(); |
| |
| if (kRootsStart <= offset && offset < kRootsEnd) { |
| uint32_t offset_in_roots_table = offset - kRootsStart; |
| |
| // Fail safe in the unlikely case of an arbitrary root-relative offset. |
| if (offset_in_roots_table % kPointerSize != 0) return nullptr; |
| |
| Heap::RootListIndex root_index = |
| static_cast<Heap::RootListIndex>(offset_in_roots_table / kPointerSize); |
| |
| HeapStringAllocator allocator; |
| StringStream accumulator(&allocator); |
| isolate_->heap()->root(root_index)->ShortPrint(&accumulator); |
| std::unique_ptr<char[]> obj_name = accumulator.ToCString(); |
| |
| SNPrintF(v8_buffer_, "root (%s)", obj_name.get()); |
| return v8_buffer_.start(); |
| } else if (kExtRefsStart <= offset && offset < kExtRefsEnd) { |
| uint32_t offset_in_extref_table = offset - kExtRefsStart; |
| |
| // Fail safe in the unlikely case of an arbitrary root-relative offset. |
| if (offset_in_extref_table % ExternalReferenceTable::EntrySize() != 0) { |
| return nullptr; |
| } |
| |
| // Likewise if the external reference table is uninitialized. |
| if (!isolate_->heap()->external_reference_table()->is_initialized()) { |
| return nullptr; |
| } |
| |
| SNPrintF(v8_buffer_, "external reference (%s)", |
| isolate_->heap()->external_reference_table()->NameFromOffset( |
| offset_in_extref_table)); |
| return v8_buffer_.start(); |
| } else { |
| return nullptr; |
| } |
| } |
| |
| static void DumpBuffer(std::ostream* os, StringBuilder* out) { |
| (*os) << out->Finalize() << std::endl; |
| out->Reset(); |
| } |
| |
| |
| static const int kOutBufferSize = 2048 + String::kMaxShortPrintLength; |
| static const int kRelocInfoPosition = 57; |
| |
| static void PrintRelocInfo(StringBuilder* out, Isolate* isolate, |
| const ExternalReferenceEncoder* ref_encoder, |
| std::ostream* os, RelocInfo* relocinfo, |
| bool first_reloc_info = true) { |
| // Indent the printing of the reloc info. |
| if (first_reloc_info) { |
| // The first reloc info is printed after the disassembled instruction. |
| out->AddPadding(' ', kRelocInfoPosition - out->position()); |
| } else { |
| // Additional reloc infos are printed on separate lines. |
| DumpBuffer(os, out); |
| out->AddPadding(' ', kRelocInfoPosition); |
| } |
| |
| RelocInfo::Mode rmode = relocinfo->rmode(); |
| if (rmode == RelocInfo::DEOPT_SCRIPT_OFFSET) { |
| out->AddFormatted(" ;; debug: deopt position, script offset '%d'", |
| static_cast<int>(relocinfo->data())); |
| } else if (rmode == RelocInfo::DEOPT_INLINING_ID) { |
| out->AddFormatted(" ;; debug: deopt position, inlining id '%d'", |
| static_cast<int>(relocinfo->data())); |
| } else if (rmode == RelocInfo::DEOPT_REASON) { |
| DeoptimizeReason reason = static_cast<DeoptimizeReason>(relocinfo->data()); |
| out->AddFormatted(" ;; debug: deopt reason '%s'", |
| DeoptimizeReasonToString(reason)); |
| } else if (rmode == RelocInfo::DEOPT_ID) { |
| out->AddFormatted(" ;; debug: deopt index %d", |
| static_cast<int>(relocinfo->data())); |
| } else if (rmode == RelocInfo::EMBEDDED_OBJECT) { |
| HeapStringAllocator allocator; |
| StringStream accumulator(&allocator); |
| relocinfo->target_object()->ShortPrint(&accumulator); |
| std::unique_ptr<char[]> obj_name = accumulator.ToCString(); |
| out->AddFormatted(" ;; object: %s", obj_name.get()); |
| } else if (rmode == RelocInfo::EXTERNAL_REFERENCE) { |
| const char* reference_name = |
| ref_encoder ? ref_encoder->NameOfAddress( |
| isolate, relocinfo->target_external_reference()) |
| : "unknown"; |
| out->AddFormatted(" ;; external reference (%s)", reference_name); |
| } else if (RelocInfo::IsCodeTargetMode(rmode)) { |
| out->AddFormatted(" ;; code:"); |
| Code* code = isolate->heap()->GcSafeFindCodeForInnerPointer( |
| relocinfo->target_address()); |
| Code::Kind kind = code->kind(); |
| if (kind == Code::STUB) { |
| // Get the STUB key and extract major and minor key. |
| uint32_t key = code->stub_key(); |
| uint32_t minor_key = CodeStub::MinorKeyFromKey(key); |
| CodeStub::Major major_key = CodeStub::GetMajorKey(code); |
| DCHECK(major_key == CodeStub::MajorKeyFromKey(key)); |
| out->AddFormatted(" %s, %s, ", Code::Kind2String(kind), |
| CodeStub::MajorName(major_key)); |
| out->AddFormatted("minor: %d", minor_key); |
| } else if (code->is_builtin()) { |
| out->AddFormatted(" Builtin::%s", Builtins::name(code->builtin_index())); |
| } else { |
| out->AddFormatted(" %s", Code::Kind2String(kind)); |
| } |
| } else if (RelocInfo::IsRuntimeEntry(rmode) && isolate && |
| isolate->deoptimizer_data() != nullptr) { |
| // A runtime entry relocinfo might be a deoptimization bailout. |
| Address addr = relocinfo->target_address(); |
| DeoptimizeKind type; |
| if (Deoptimizer::IsDeoptimizationEntry(isolate, addr, &type)) { |
| int id = relocinfo->GetDeoptimizationId(isolate, type); |
| out->AddFormatted(" ;; %s deoptimization bailout %d", |
| Deoptimizer::MessageFor(type), id); |
| } else { |
| out->AddFormatted(" ;; %s", RelocInfo::RelocModeName(rmode)); |
| } |
| } else { |
| out->AddFormatted(" ;; %s", RelocInfo::RelocModeName(rmode)); |
| } |
| } |
| |
| static int DecodeIt(Isolate* isolate, ExternalReferenceEncoder* ref_encoder, |
| std::ostream* os, CodeReference code, |
| const V8NameConverter& converter, byte* begin, byte* end, |
| Address current_pc) { |
| v8::internal::EmbeddedVector<char, 128> decode_buffer; |
| v8::internal::EmbeddedVector<char, kOutBufferSize> out_buffer; |
| StringBuilder out(out_buffer.start(), out_buffer.length()); |
| byte* pc = begin; |
| disasm::Disassembler d(converter, |
| disasm::Disassembler::kContinueOnUnimplementedOpcode); |
| RelocIterator* it = nullptr; |
| if (!code.is_null()) { |
| it = new RelocIterator(code); |
| } else { |
| // No relocation information when printing code stubs. |
| } |
| int constants = -1; // no constants being decoded at the start |
| |
| while (pc < end) { |
| // First decode instruction so that we know its length. |
| byte* prev_pc = pc; |
| if (constants > 0) { |
| SNPrintF(decode_buffer, |
| "%08x constant", |
| *reinterpret_cast<int32_t*>(pc)); |
| constants--; |
| pc += 4; |
| } else { |
| int num_const = d.ConstantPoolSizeAt(pc); |
| if (num_const >= 0) { |
| SNPrintF(decode_buffer, |
| "%08x constant pool begin (num_const = %d)", |
| *reinterpret_cast<int32_t*>(pc), num_const); |
| constants = num_const; |
| pc += 4; |
| } else if (it != nullptr && !it->done() && |
| it->rinfo()->pc() == reinterpret_cast<Address>(pc) && |
| it->rinfo()->rmode() == RelocInfo::INTERNAL_REFERENCE) { |
| // raw pointer embedded in code stream, e.g., jump table |
| byte* ptr = *reinterpret_cast<byte**>(pc); |
| SNPrintF( |
| decode_buffer, "%08" V8PRIxPTR " jump table entry %4" PRIuS, |
| reinterpret_cast<intptr_t>(ptr), static_cast<size_t>(ptr - begin)); |
| pc += sizeof(ptr); |
| } else { |
| decode_buffer[0] = '\0'; |
| pc += d.InstructionDecode(decode_buffer, pc); |
| } |
| } |
| |
| // Collect RelocInfo for this instruction (prev_pc .. pc-1) |
| std::vector<const char*> comments; |
| std::vector<Address> pcs; |
| std::vector<RelocInfo::Mode> rmodes; |
| std::vector<intptr_t> datas; |
| if (it != nullptr) { |
| while (!it->done() && it->rinfo()->pc() < reinterpret_cast<Address>(pc)) { |
| if (RelocInfo::IsComment(it->rinfo()->rmode())) { |
| // For comments just collect the text. |
| comments.push_back( |
| reinterpret_cast<const char*>(it->rinfo()->data())); |
| } else { |
| // For other reloc info collect all data. |
| pcs.push_back(it->rinfo()->pc()); |
| rmodes.push_back(it->rinfo()->rmode()); |
| datas.push_back(it->rinfo()->data()); |
| } |
| it->next(); |
| } |
| } |
| |
| // Comments. |
| for (size_t i = 0; i < comments.size(); i++) { |
| out.AddFormatted(" %s", comments[i]); |
| DumpBuffer(os, &out); |
| } |
| |
| // Instruction address and instruction offset. |
| if (FLAG_log_colour && reinterpret_cast<Address>(prev_pc) == current_pc) { |
| // If this is the given "current" pc, make it yellow and bold. |
| out.AddFormatted("\033[33;1m"); |
| } |
| out.AddFormatted("%p %4" V8PRIxPTRDIFF " ", static_cast<void*>(prev_pc), |
| prev_pc - begin); |
| |
| // Instruction. |
| out.AddFormatted("%s", decode_buffer.start()); |
| |
| // Print all the reloc info for this instruction which are not comments. |
| for (size_t i = 0; i < pcs.size(); i++) { |
| // Put together the reloc info |
| const CodeReference& host = code; |
| Address constant_pool = |
| host.is_null() ? kNullAddress : host.constant_pool(); |
| RelocInfo relocinfo(pcs[i], rmodes[i], datas[i], nullptr, constant_pool); |
| |
| bool first_reloc_info = (i == 0); |
| PrintRelocInfo(&out, isolate, ref_encoder, os, &relocinfo, |
| first_reloc_info); |
| } |
| |
| // If this is a constant pool load and we haven't found any RelocInfo |
| // already, check if we can find some RelocInfo for the target address in |
| // the constant pool. |
| if (pcs.empty() && !code.is_null()) { |
| RelocInfo dummy_rinfo(reinterpret_cast<Address>(prev_pc), RelocInfo::NONE, |
| 0, nullptr); |
| if (dummy_rinfo.IsInConstantPool()) { |
| Address constant_pool_entry_address = |
| dummy_rinfo.constant_pool_entry_address(); |
| RelocIterator reloc_it(code); |
| while (!reloc_it.done()) { |
| if (reloc_it.rinfo()->IsInConstantPool() && |
| (reloc_it.rinfo()->constant_pool_entry_address() == |
| constant_pool_entry_address)) { |
| PrintRelocInfo(&out, isolate, ref_encoder, os, reloc_it.rinfo()); |
| break; |
| } |
| reloc_it.next(); |
| } |
| } |
| } |
| |
| if (FLAG_log_colour && reinterpret_cast<Address>(prev_pc) == current_pc) { |
| out.AddFormatted("\033[m"); |
| } |
| |
| DumpBuffer(os, &out); |
| } |
| |
| // Emit comments following the last instruction (if any). |
| if (it != nullptr) { |
| for ( ; !it->done(); it->next()) { |
| if (RelocInfo::IsComment(it->rinfo()->rmode())) { |
| out.AddFormatted(" %s", |
| reinterpret_cast<const char*>(it->rinfo()->data())); |
| DumpBuffer(os, &out); |
| } |
| } |
| } |
| |
| delete it; |
| return static_cast<int>(pc - begin); |
| } |
| |
| int Disassembler::Decode(Isolate* isolate, std::ostream* os, byte* begin, |
| byte* end, CodeReference code, Address current_pc) { |
| V8NameConverter v8NameConverter(isolate, code); |
| bool decode_off_heap = isolate && InstructionStream::PcIsOffHeap( |
| isolate, bit_cast<Address>(begin)); |
| CodeReference code_ref = decode_off_heap ? CodeReference() : code; |
| if (isolate) { |
| // We have an isolate, so support external reference names. |
| SealHandleScope shs(isolate); |
| DisallowHeapAllocation no_alloc; |
| ExternalReferenceEncoder ref_encoder(isolate); |
| return DecodeIt(isolate, &ref_encoder, os, code_ref, v8NameConverter, begin, |
| end, current_pc); |
| } else { |
| // No isolate => isolate-independent code. No external reference names. |
| return DecodeIt(nullptr, nullptr, os, code_ref, v8NameConverter, begin, end, |
| current_pc); |
| } |
| } |
| |
| #else // ENABLE_DISASSEMBLER |
| |
| int Disassembler::Decode(Isolate* isolate, std::ostream* os, byte* begin, |
| byte* end, CodeReference code, Address current_pc) { |
| return 0; |
| } |
| |
| #endif // ENABLE_DISASSEMBLER |
| |
| } // namespace internal |
| } // namespace v8 |