deps: update V8 to 7.6.303.28

PR-URL: https://github.com/nodejs/node/pull/28016
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Refael Ackermann (רפאל פלחי) <refack@gmail.com>
Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: Michael Dawson <michael_dawson@ca.ibm.com>
Reviewed-By: Jiawen Geng <technicalcute@gmail.com>

1 files changed, 446 insertions, 0 deletions

diff --git a/deps/v8/src/diagnostics/disassembler.cc b/deps/v8/src/diagnostics/disassembler.cc
new file mode 100644
index 0000000000..8307ef3ff4
--- /dev/null
+++ b/deps/v8/src/diagnostics/disassembler.cc
@@ -0,0 +1,446 @@
+// 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/diagnostics/disassembler.h"
+
+#include <memory>
+#include <unordered_map>
+#include <vector>
+
+#include "src/codegen/assembler-inl.h"
+#include "src/codegen/code-comments.h"
+#include "src/codegen/code-reference.h"
+#include "src/codegen/macro-assembler.h"
+#include "src/debug/debug.h"
+#include "src/deoptimizer/deoptimizer.h"
+#include "src/diagnostics/disasm.h"
+#include "src/execution/isolate-data.h"
+#include "src/ic/ic.h"
+#include "src/objects/objects-inl.h"
+#include "src/snapshot/embedded/embedded-data.h"
+#include "src/snapshot/serializer-common.h"
+#include "src/strings/string-stream.h"
+#include "src/utils/vector.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:
+  void InitExternalRefsCache() const;
+
+  Isolate* isolate_;
+  CodeReference code_;
+
+  EmbeddedVector<char, 128> v8_buffer_;
+
+  // Map from root-register relative offset of the external reference value to
+  // the external reference name (stored in the external reference table).
+  // This cache is used to recognize [root_reg + offs] patterns as direct
+  // access to certain external reference's value.
+  mutable std::unordered_map<int, const char*> directly_accessed_external_refs_;
+};
+
+void V8NameConverter::InitExternalRefsCache() const {
+  ExternalReferenceTable* external_reference_table =
+      isolate_->external_reference_table();
+  if (!external_reference_table->is_initialized()) return;
+
+  base::AddressRegion addressable_region =
+      isolate_->root_register_addressable_region();
+  Address isolate_root = isolate_->isolate_root();
+
+  for (uint32_t i = 0; i < ExternalReferenceTable::kSize; i++) {
+    Address address = external_reference_table->address(i);
+    if (addressable_region.contains(address)) {
+      int offset = static_cast<int>(address - isolate_root);
+      const char* name = external_reference_table->name(i);
+      directly_accessed_external_refs_.insert({offset, name});
+    }
+  }
+}
+
+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_.begin();
+    }
+
+    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_.begin();
+    }
+
+    wasm::WasmCodeRefScope wasm_code_ref_scope;
+    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_.begin();
+    }
+  }
+
+  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 kRootsTableStart = IsolateData::roots_table_offset();
+  const unsigned kRootsTableSize = sizeof(RootsTable);
+  const int kExtRefsTableStart = IsolateData::external_reference_table_offset();
+  const unsigned kExtRefsTableSize = ExternalReferenceTable::kSizeInBytes;
+  const int kBuiltinsTableStart = IsolateData::builtins_table_offset();
+  const unsigned kBuiltinsTableSize =
+      Builtins::builtin_count * kSystemPointerSize;
+
+  if (static_cast<unsigned>(offset - kRootsTableStart) < kRootsTableSize) {
+    uint32_t offset_in_roots_table = offset - kRootsTableStart;
+
+    // Fail safe in the unlikely case of an arbitrary root-relative offset.
+    if (offset_in_roots_table % kSystemPointerSize != 0) return nullptr;
+
+    RootIndex root_index =
+        static_cast<RootIndex>(offset_in_roots_table / kSystemPointerSize);
+
+    SNPrintF(v8_buffer_, "root (%s)", RootsTable::name(root_index));
+    return v8_buffer_.begin();
+
+  } else if (static_cast<unsigned>(offset - kExtRefsTableStart) <
+             kExtRefsTableSize) {
+    uint32_t offset_in_extref_table = offset - kExtRefsTableStart;
+
+    // Fail safe in the unlikely case of an arbitrary root-relative offset.
+    if (offset_in_extref_table % ExternalReferenceTable::kEntrySize != 0) {
+      return nullptr;
+    }
+
+    // Likewise if the external reference table is uninitialized.
+    if (!isolate_->external_reference_table()->is_initialized()) {
+      return nullptr;
+    }
+
+    SNPrintF(v8_buffer_, "external reference (%s)",
+             isolate_->external_reference_table()->NameFromOffset(
+                 offset_in_extref_table));
+    return v8_buffer_.begin();
+
+  } else if (static_cast<unsigned>(offset - kBuiltinsTableStart) <
+             kBuiltinsTableSize) {
+    uint32_t offset_in_builtins_table = (offset - kBuiltinsTableStart);
+
+    Builtins::Name builtin_id = static_cast<Builtins::Name>(
+        offset_in_builtins_table / kSystemPointerSize);
+
+    const char* name = Builtins::name(builtin_id);
+    SNPrintF(v8_buffer_, "builtin (%s)", name);
+    return v8_buffer_.begin();
+
+  } else {
+    // It must be a direct access to one of the external values.
+    if (directly_accessed_external_refs_.empty()) {
+      InitExternalRefsCache();
+    }
+
+    auto iter = directly_accessed_external_refs_.find(offset);
+    if (iter != directly_accessed_external_refs_.end()) {
+      SNPrintF(v8_buffer_, "external value (%s)", iter->second);
+      return v8_buffer_.begin();
+    }
+    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, CodeReference host,
+                           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 (RelocInfo::IsEmbeddedObjectMode(rmode)) {
+    HeapStringAllocator allocator;
+    StringStream accumulator(&allocator);
+    relocinfo->target_object().ShortPrint(&accumulator);
+    std::unique_ptr<char[]> obj_name = accumulator.ToCString();
+    const bool is_compressed = RelocInfo::IsCompressedEmbeddedObject(rmode);
+    out->AddFormatted("    ;; %sobject: %s",
+                      is_compressed ? "(compressed) " : "", 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 (code.is_builtin()) {
+      out->AddFormatted(" Builtin::%s", Builtins::name(code.builtin_index()));
+    } else {
+      out->AddFormatted(" %s", Code::Kind2String(kind));
+    }
+  } else if (RelocInfo::IsWasmStubCall(rmode) && host.is_wasm_code()) {
+    // Host is isolate-independent, try wasm native module instead.
+    const char* runtime_stub_name =
+        host.as_wasm_code()->native_module()->GetRuntimeStubName(
+            relocinfo->wasm_stub_call_address());
+    out->AddFormatted("    ;; wasm stub: %s", runtime_stub_name);
+  } 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)) {
+      out->AddFormatted("    ;; %s deoptimization bailout",
+                        Deoptimizer::MessageFor(type));
+    } 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) {
+  CHECK(!code.is_null());
+  v8::internal::EmbeddedVector<char, 128> decode_buffer;
+  v8::internal::EmbeddedVector<char, kOutBufferSize> out_buffer;
+  StringBuilder out(out_buffer.begin(), out_buffer.length());
+  byte* pc = begin;
+  disasm::Disassembler d(converter,
+                         disasm::Disassembler::kContinueOnUnimplementedOpcode);
+  RelocIterator* it = nullptr;
+  CodeCommentsIterator cit(code.code_comments(), code.code_comments_size());
+  // Relocation exists if we either have no isolate (wasm code),
+  // or we have an isolate and it is not an off-heap instruction stream.
+  if (!isolate ||
+      !InstructionStream::PcIsOffHeap(isolate, bit_cast<Address>(begin))) {
+    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 %4zu",
+                 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)) {
+        // Collect all data.
+        pcs.push_back(it->rinfo()->pc());
+        rmodes.push_back(it->rinfo()->rmode());
+        datas.push_back(it->rinfo()->data());
+        it->next();
+      }
+    }
+    while (cit.HasCurrent() &&
+           cit.GetPCOffset() < static_cast<Address>(pc - begin)) {
+      comments.push_back(cit.GetComment());
+      cit.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.begin());
+
+    // 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();
+      Code code_pointer;
+      if (!host.is_null() && host.is_js()) {
+        code_pointer = *host.as_js_code();
+      }
+
+      RelocInfo relocinfo(pcs[i], rmodes[i], datas[i], code_pointer,
+                          constant_pool);
+
+      bool first_reloc_info = (i == 0);
+      PrintRelocInfo(&out, isolate, ref_encoder, os, code, &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, Code());
+      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, code,
+                           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).
+  while (cit.HasCurrent() &&
+         cit.GetPCOffset() < static_cast<Address>(pc - begin)) {
+    out.AddFormatted("                  %s", cit.GetComment());
+    DumpBuffer(os, &out);
+    cit.Next();
+  }
+
+  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);
+  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, v8NameConverter, begin,
+                    end, current_pc);
+  } else {
+    // No isolate => isolate-independent code. No external reference names.
+    return DecodeIt(nullptr, nullptr, os, code, 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