[regexp] Remove dead DispatchTableConstructor

Bug: v8:9359
Change-Id: I1b490c928ed884f4ad33e005699f98614be75233
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1662306
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Auto-Submit: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Peter Marshall <petermarshall@chromium.org>
Cr-Commit-Position: refs/heads/master@{#62242}

src/regexp/regexp-compiler.cc

@@ -213,15 +213,6 @@ int TextElement::length() const {
   UNREACHABLE();
 }
 
-DispatchTable* ChoiceNode::GetTable(bool ignore_case) {
-  if (table_ == nullptr) {
-    table_ = new (zone()) DispatchTable(zone());
-    DispatchTableConstructor cons(table_, ignore_case, zone());
-    cons.BuildTable(this);
-  }
-  return table_;
-}
-
 class RecursionCheck {
  public:
   explicit RecursionCheck(RegExpCompiler* compiler) : compiler_(compiler) {
@@ -3606,107 +3597,6 @@ void TextNode::FillInBMInfo(Isolate* isolate, int initial_offset, int budget,
   if (initial_offset == 0) set_bm_info(not_at_start, bm);
 }
 
-// -------------------------------------------------------------------
-// Dispatch table construction
-
-void DispatchTableConstructor::VisitEnd(EndNode* that) {
-  AddRange(CharacterRange::Everything());
-}
-
-void DispatchTableConstructor::BuildTable(ChoiceNode* node) {
-  node->set_being_calculated(true);
-  ZoneList<GuardedAlternative>* alternatives = node->alternatives();
-  for (int i = 0; i < alternatives->length(); i++) {
-    set_choice_index(i);
-    alternatives->at(i).node()->Accept(this);
-  }
-  node->set_being_calculated(false);
-}
-
-class AddDispatchRange {
- public:
-  explicit AddDispatchRange(DispatchTableConstructor* constructor)
-      : constructor_(constructor) {}
-  void Call(uc32 from, DispatchTable::Entry entry);
-
- private:
-  DispatchTableConstructor* constructor_;
-};
-
-void AddDispatchRange::Call(uc32 from, DispatchTable::Entry entry) {
-  constructor_->AddRange(CharacterRange::Range(from, entry.to()));
-}
-
-void DispatchTableConstructor::VisitChoice(ChoiceNode* node) {
-  if (node->being_calculated()) return;
-  DispatchTable* table = node->GetTable(ignore_case_);
-  AddDispatchRange adder(this);
-  table->ForEach(&adder);
-}
-
-void DispatchTableConstructor::VisitBackReference(BackReferenceNode* that) {
-  // TODO(160): Find the node that we refer back to and propagate its start
-  // set back to here.  For now we just accept anything.
-  AddRange(CharacterRange::Everything());
-}
-
-void DispatchTableConstructor::VisitAssertion(AssertionNode* that) {
-  RegExpNode* target = that->on_success();
-  target->Accept(this);
-}
-
-static int CompareRangeByFrom(const CharacterRange* a,
-                              const CharacterRange* b) {
-  return Compare<uc16>(a->from(), b->from());
-}
-
-void DispatchTableConstructor::AddInverse(ZoneList<CharacterRange>* ranges) {
-  ranges->Sort(CompareRangeByFrom);
-  uc16 last = 0;
-  for (int i = 0; i < ranges->length(); i++) {
-    CharacterRange range = ranges->at(i);
-    if (last < range.from())
-      AddRange(CharacterRange::Range(last, range.from() - 1));
-    if (range.to() >= last) {
-      if (range.to() == String::kMaxCodePoint) {
-        return;
-      } else {
-        last = range.to() + 1;
-      }
-    }
-  }
-  AddRange(CharacterRange::Range(last, String::kMaxCodePoint));
-}
-
-void DispatchTableConstructor::VisitText(TextNode* that) {
-  TextElement elm = that->elements()->at(0);
-  switch (elm.text_type()) {
-    case TextElement::ATOM: {
-      uc16 c = elm.atom()->data()[0];
-      AddRange(CharacterRange::Range(c, c));
-      break;
-    }
-    case TextElement::CHAR_CLASS: {
-      RegExpCharacterClass* tree = elm.char_class();
-      ZoneList<CharacterRange>* ranges = tree->ranges(that->zone());
-      if (tree->is_negated()) {
-        AddInverse(ranges);
-      } else {
-        for (int i = 0; i < ranges->length(); i++) AddRange(ranges->at(i));
-      }
-      break;
-    }
-    default: {
-      UNIMPLEMENTED();
-    }
-  }
-}
-
-void DispatchTableConstructor::VisitAction(ActionNode* that) {
-  RegExpNode* target = that->on_success();
-  target->Accept(this);
-}
-
 // static
 RegExpNode* RegExpCompiler::OptionallyStepBackToLeadSurrogate(
     RegExpCompiler* compiler, RegExpNode* on_success, JSRegExp::Flags flags) {

src/regexp/regexp-compiler.h

@@ -164,38 +164,6 @@ class DispatchTable : public ZoneObject {
   ZoneSplayTree<Config> tree_;
 };
 
-// Node visitor used to add the start set of the alternatives to the
-// dispatch table of a choice node.
-class V8_EXPORT_PRIVATE DispatchTableConstructor : public NodeVisitor {
- public:
-  DispatchTableConstructor(DispatchTable* table, bool ignore_case, Zone* zone)
-      : table_(table),
-        choice_index_(-1),
-        ignore_case_(ignore_case),
-        zone_(zone) {}
-
-  void BuildTable(ChoiceNode* node);
-
-  void AddRange(CharacterRange range) {
-    table()->AddRange(range, choice_index_, zone_);
-  }
-
-  void AddInverse(ZoneList<CharacterRange>* ranges);
-
-#define DECLARE_VISIT(Type) virtual void Visit##Type(Type##Node* that);
-  FOR_EACH_NODE_TYPE(DECLARE_VISIT)
-#undef DECLARE_VISIT
-
-  DispatchTable* table() { return table_; }
-  void set_choice_index(int value) { choice_index_ = value; }
-
- protected:
-  DispatchTable* table_;
-  int choice_index_;
-  bool ignore_case_;
-  Zone* zone_;
-};
-
 // Details of a quick mask-compare check that can look ahead in the
 // input stream.
 class QuickCheckDetails {

src/regexp/regexp-dotprinter.cc

@@ -18,8 +18,7 @@ namespace internal {
 
 class DotPrinterImpl : public NodeVisitor {
  public:
-  DotPrinterImpl(std::ostream& os, bool ignore_case)  // NOLINT
-      : os_(os), ignore_case_(ignore_case) {}
+  explicit DotPrinterImpl(std::ostream& os) : os_(os) {}
   void PrintNode(const char* label, RegExpNode* node);
   void Visit(RegExpNode* node);
   void PrintAttributes(RegExpNode* from);
@@ -29,7 +28,6 @@ class DotPrinterImpl : public NodeVisitor {
 #undef DECLARE_VISIT
  private:
   std::ostream& os_;
-  bool ignore_case_;
 };
 
 void DotPrinterImpl::PrintNode(const char* label, RegExpNode* node) {
@@ -153,22 +151,11 @@ void DotPrinterImpl::PrintAttributes(RegExpNode* that) {
       << " [style=dashed, color=grey, arrowhead=none];\n";
 }
 
-static const bool kPrintDispatchTable = false;
 void DotPrinterImpl::VisitChoice(ChoiceNode* that) {
-  if (kPrintDispatchTable) {
-    os_ << "  n" << that << " [shape=Mrecord, label=\"";
-    TableEntryHeaderPrinter header_printer(os_);
-    that->GetTable(ignore_case_)->ForEach(&header_printer);
-    os_ << "\"]\n";
-    PrintAttributes(that);
-    TableEntryBodyPrinter body_printer(os_, that);
-    that->GetTable(ignore_case_)->ForEach(&body_printer);
-  } else {
-    os_ << "  n" << that << " [shape=Mrecord, label=\"?\"];\n";
-    for (int i = 0; i < that->alternatives()->length(); i++) {
-      GuardedAlternative alt = that->alternatives()->at(i);
-      os_ << "  n" << that << " -> n" << alt.node();
-    }
+  os_ << "  n" << that << " [shape=Mrecord, label=\"?\"];\n";
+  for (int i = 0; i < that->alternatives()->length(); i++) {
+    GuardedAlternative alt = that->alternatives()->at(i);
+    os_ << "  n" << that << " -> n" << alt.node();
   }
   for (int i = 0; i < that->alternatives()->length(); i++) {
     GuardedAlternative alt = that->alternatives()->at(i);
@@ -326,11 +313,10 @@ void DispatchTable::Dump() {
 
 #endif  // DEBUG
 
-void DotPrinter::DotPrint(const char* label, RegExpNode* node,
-                          bool ignore_case) {
+void DotPrinter::DotPrint(const char* label, RegExpNode* node) {
 #ifdef DEBUG
   StdoutStream os;
-  DotPrinterImpl printer(os, ignore_case);
+  DotPrinterImpl printer(os);
   printer.PrintNode(label, node);
 #endif  // DEBUG
 }

src/regexp/regexp-dotprinter.h

@@ -14,7 +14,7 @@ class RegExpNode;
 
 class DotPrinter final : public AllStatic {
  public:
-  static void DotPrint(const char* label, RegExpNode* node, bool ignore_case);
+  static void DotPrint(const char* label, RegExpNode* node);
 };
 
 }  // namespace internal

src/regexp/regexp-nodes.h

@@ -533,7 +533,6 @@ class ChoiceNode : public RegExpNode {
       : RegExpNode(zone),
         alternatives_(new (zone)
                           ZoneList<GuardedAlternative>(expected_size, zone)),
-        table_(nullptr),
         not_at_start_(false),
         being_calculated_(false) {}
   void Accept(NodeVisitor* visitor) override;
@@ -541,7 +540,6 @@ class ChoiceNode : public RegExpNode {
     alternatives()->Add(node, zone());
   }
   ZoneList<GuardedAlternative>* alternatives() { return alternatives_; }
-  DispatchTable* GetTable(bool ignore_case);
   void Emit(RegExpCompiler* compiler, Trace* trace) override;
   int EatsAtLeast(int still_to_find, int budget, bool not_at_start) override;
   int EatsAtLeastHelper(int still_to_find, int budget,
@@ -567,8 +565,8 @@ class ChoiceNode : public RegExpNode {
   ZoneList<GuardedAlternative>* alternatives_;
 
  private:
-  friend class DispatchTableConstructor;
   friend class Analysis;
+
   void GenerateGuard(RegExpMacroAssembler* macro_assembler, Guard* guard,
                      Trace* trace);
   int CalculatePreloadCharacters(RegExpCompiler* compiler, int eats_at_least);
@@ -588,7 +586,7 @@ class ChoiceNode : public RegExpNode {
   void EmitChoices(RegExpCompiler* compiler,
                    AlternativeGenerationList* alt_gens, int first_choice,
                    Trace* trace, PreloadState* preloads);
-  DispatchTable* table_;
+
   // If true, this node is never checked at the start of the input.
   // Allows a new trace to start with at_start() set to false.
   bool not_at_start_;

src/regexp/regexp.cc

@@ -598,9 +598,8 @@ Handle<RegExpMatchInfo> RegExp::SetLastMatchInfo(
 }
 
 // static
-void RegExp::DotPrintForTesting(const char* label, RegExpNode* node,
-                                bool ignore_case) {
-  DotPrinter::DotPrint(label, node, ignore_case);
+void RegExp::DotPrintForTesting(const char* label, RegExpNode* node) {
+  DotPrinter::DotPrint(label, node);
 }
 
 namespace {

src/regexp/regexp.h

@@ -103,8 +103,7 @@ class RegExp final : public AllStatic {
                                                   bool is_one_byte);
 
   V8_EXPORT_PRIVATE static void DotPrintForTesting(const char* label,
-                                                   RegExpNode* node,
-                                                   bool ignore_case);
+                                                   RegExpNode* node);
 
   static const int kRegExpTooLargeToOptimize = 20 * KB;
 };

test/cctest/test-regexp.cc

@@ -560,9 +560,7 @@ static void Execute(const char* input, bool multiline, bool unicode,
   RegExpNode* node = Compile(input, multiline, unicode, is_one_byte, &zone);
   USE(node);
 #ifdef DEBUG
-  if (dot_output) {
-    RegExp::DotPrintForTesting(input, node, false);
-  }
+  if (dot_output) RegExp::DotPrintForTesting(input, node);
 #endif  // DEBUG
 }
 
@@ -1432,43 +1430,6 @@ TEST(MacroAssembler) {
   CHECK_EQ(42, captures[0]);
 }
 
-TEST(AddInverseToTable) {
-  static const int kLimit = 1000;
-  static const int kRangeCount = 16;
-  for (int t = 0; t < 10; t++) {
-    Zone zone(CcTest::i_isolate()->allocator(), ZONE_NAME);
-    ZoneList<CharacterRange>* ranges =
-        new(&zone) ZoneList<CharacterRange>(kRangeCount, &zone);
-    for (int i = 0; i < kRangeCount; i++) {
-      int from = PseudoRandom(t + 87, i + 25) % kLimit;
-      int to = from + (PseudoRandom(i + 87, t + 25) % (kLimit / 20));
-      if (to > kLimit) to = kLimit;
-      ranges->Add(CharacterRange::Range(from, to), &zone);
-    }
-    DispatchTable table(&zone);
-    DispatchTableConstructor cons(&table, false, &zone);
-    cons.set_choice_index(0);
-    cons.AddInverse(ranges);
-    for (int i = 0; i < kLimit; i++) {
-      bool is_on = false;
-      for (int j = 0; !is_on && j < kRangeCount; j++)
-        is_on = ranges->at(j).Contains(i);
-      OutSet* set = table.Get(i);
-      CHECK_EQ(is_on, set->Get(0) == false);
-    }
-  }
-  Zone zone(CcTest::i_isolate()->allocator(), ZONE_NAME);
-  ZoneList<CharacterRange>* ranges =
-      new(&zone) ZoneList<CharacterRange>(1, &zone);
-  ranges->Add(CharacterRange::Range(0xFFF0, 0xFFFE), &zone);
-  DispatchTable table(&zone);
-  DispatchTableConstructor cons(&table, false, &zone);
-  cons.set_choice_index(0);
-  cons.AddInverse(ranges);
-  CHECK(!table.Get(0xFFFE)->Get(0));
-  CHECK(table.Get(0xFFFF)->Get(0));
-}
-
 #ifndef V8_INTL_SUPPORT
 static uc32 canonicalize(uc32 c) {
   unibrow::uchar canon[unibrow::Ecma262Canonicalize::kMaxWidth];