| Index: runtime/vm/regexp.cc
|
| diff --git a/runtime/vm/regexp.cc b/runtime/vm/regexp.cc
|
| new file mode 100644
|
| index 0000000000000000000000000000000000000000..534e0c5072dc380457539422f1121bdecd81b0a8
|
| --- /dev/null
|
| +++ b/runtime/vm/regexp.cc
|
| @@ -0,0 +1,5438 @@
|
| +// Copyright (c) 2014, the Dart project authors. Please see the AUTHORS file
|
| +// for details. All rights reserved. Use of this source code is governed by a
|
| +// BSD-style license that can be found in the LICENSE file.
|
| +
|
| +#include "vm/regexp.h"
|
| +
|
| +// SNIP
|
| +
|
| +namespace dart {
|
| +
|
| +// SNIP
|
| +
|
| +// -------------------------------------------------------------------
|
| +// Implementation of the Irregexp regular expression engine.
|
| +//
|
| +// The Irregexp regular expression engine is intended to be a complete
|
| +// implementation of ECMAScript regular expressions. It generates either
|
| +// bytecodes or native code.
|
| +
|
| +// The Irregexp regexp engine is structured in three steps.
|
| +// 1) The parser generates an abstract syntax tree. See ast.cc.
|
| +// 2) From the AST a node network is created. The nodes are all
|
| +// subclasses of RegExpNode. The nodes represent states when
|
| +// executing a regular expression. Several optimizations are
|
| +// performed on the node network.
|
| +// 3) From the nodes we generate either byte codes or native code
|
| +// that can actually execute the regular expression (perform
|
| +// the search). The code generation step is described in more
|
| +// detail below.
|
| +
|
| +// Code generation.
|
| +//
|
| +// The nodes are divided into four main categories.
|
| +// * Choice nodes
|
| +// These represent places where the regular expression can
|
| +// match in more than one way. For example on entry to an
|
| +// alternation (foo|bar) or a repetition (*, +, ? or {}).
|
| +// * Action nodes
|
| +// These represent places where some action should be
|
| +// performed. Examples include recording the current position
|
| +// in the input string to a register (in order to implement
|
| +// captures) or other actions on register for example in order
|
| +// to implement the counters needed for {} repetitions.
|
| +// * Matching nodes
|
| +// These attempt to match some element part of the input string.
|
| +// Examples of elements include character classes, plain strings
|
| +// or back references.
|
| +// * End nodes
|
| +// These are used to implement the actions required on finding
|
| +// a successful match or failing to find a match.
|
| +//
|
| +// The code generated (whether as byte codes or native code) maintains
|
| +// some state as it runs. This consists of the following elements:
|
| +//
|
| +// * The capture registers. Used for string captures.
|
| +// * Other registers. Used for counters etc.
|
| +// * The current position.
|
| +// * The stack of backtracking information. Used when a matching node
|
| +// fails to find a match and needs to try an alternative.
|
| +//
|
| +// Conceptual regular expression execution model:
|
| +//
|
| +// There is a simple conceptual model of regular expression execution
|
| +// which will be presented first. The actual code generated is a more
|
| +// efficient simulation of the simple conceptual model:
|
| +//
|
| +// * Choice nodes are implemented as follows:
|
| +// For each choice except the last {
|
| +// push current position
|
| +// push backtrack code location
|
| +// <generate code to test for choice>
|
| +// backtrack code location:
|
| +// pop current position
|
| +// }
|
| +// <generate code to test for last choice>
|
| +//
|
| +// * Actions nodes are generated as follows
|
| +// <push affected registers on backtrack stack>
|
| +// <generate code to perform action>
|
| +// push backtrack code location
|
| +// <generate code to test for following nodes>
|
| +// backtrack code location:
|
| +// <pop affected registers to restore their state>
|
| +// <pop backtrack location from stack and go to it>
|
| +//
|
| +// * Matching nodes are generated as follows:
|
| +// if input string matches at current position
|
| +// update current position
|
| +// <generate code to test for following nodes>
|
| +// else
|
| +// <pop backtrack location from stack and go to it>
|
| +//
|
| +// Thus it can be seen that the current position is saved and restored
|
| +// by the choice nodes, whereas the registers are saved and restored by
|
| +// by the action nodes that manipulate them.
|
| +//
|
| +// The other interesting aspect of this model is that nodes are generated
|
| +// at the point where they are needed by a recursive call to Emit(). If
|
| +// the node has already been code generated then the Emit() call will
|
| +// generate a jump to the previously generated code instead. In order to
|
| +// limit recursion it is possible for the Emit() function to put the node
|
| +// on a work list for later generation and instead generate a jump. The
|
| +// destination of the jump is resolved later when the code is generated.
|
| +//
|
| +// Actual regular expression code generation.
|
| +//
|
| +// Code generation is actually more complicated than the above. In order
|
| +// to improve the efficiency of the generated code some optimizations are
|
| +// performed
|
| +//
|
| +// * Choice nodes have 1-character lookahead.
|
| +// A choice node looks at the following character and eliminates some of
|
| +// the choices immediately based on that character. This is not yet
|
| +// implemented.
|
| +// * Simple greedy loops store reduced backtracking information.
|
| +// A quantifier like /.*foo/m will greedily match the whole input. It will
|
| +// then need to backtrack to a point where it can match "foo". The naive
|
| +// implementation of this would push each character position onto the
|
| +// backtracking stack, then pop them off one by one. This would use space
|
| +// proportional to the length of the input string. However since the "."
|
| +// can only match in one way and always has a constant length (in this case
|
| +// of 1) it suffices to store the current position on the top of the stack
|
| +// once. Matching now becomes merely incrementing the current position and
|
| +// backtracking becomes decrementing the current position and checking the
|
| +// result against the stored current position. This is faster and saves
|
| +// space.
|
| +// * The current state is virtualized.
|
| +// This is used to defer expensive operations until it is clear that they
|
| +// are needed and to generate code for a node more than once, allowing
|
| +// specialized an efficient versions of the code to be created. This is
|
| +// explained in the section below.
|
| +//
|
| +// Execution state virtualization.
|
| +//
|
| +// Instead of emitting code, nodes that manipulate the state can record their
|
| +// manipulation in an object called the Trace. The Trace object can record a
|
| +// current position offset, an optional backtrack code location on the top of
|
| +// the virtualized backtrack stack and some register changes. When a node is
|
| +// to be emitted it can flush the Trace or update it. Flushing the Trace
|
| +// will emit code to bring the actual state into line with the virtual state.
|
| +// Avoiding flushing the state can postpone some work (e.g. updates of capture
|
| +// registers). Postponing work can save time when executing the regular
|
| +// expression since it may be found that the work never has to be done as a
|
| +// failure to match can occur. In addition it is much faster to jump to a
|
| +// known backtrack code location than it is to pop an unknown backtrack
|
| +// location from the stack and jump there.
|
| +//
|
| +// The virtual state found in the Trace affects code generation. For example
|
| +// the virtual state contains the difference between the actual current
|
| +// position and the virtual current position, and matching code needs to use
|
| +// this offset to attempt a match in the correct location of the input
|
| +// string. Therefore code generated for a non-trivial trace is specialized
|
| +// to that trace. The code generator therefore has the ability to generate
|
| +// code for each node several times. In order to limit the size of the
|
| +// generated code there is an arbitrary limit on how many specialized sets of
|
| +// code may be generated for a given node. If the limit is reached, the
|
| +// trace is flushed and a generic version of the code for a node is emitted.
|
| +// This is subsequently used for that node. The code emitted for non-generic
|
| +// trace is not recorded in the node and so it cannot currently be reused in
|
| +// the event that code generation is requested for an identical trace.
|
| +
|
| +
|
| +void RegExpTree::AppendToText(RegExpText* text, Zone* zone) {
|
| + UNREACHABLE();
|
| +}
|
| +
|
| +
|
| +void RegExpAtom::AppendToText(RegExpText* text, Zone* zone) {
|
| + text->AddElement(TextElement::Atom(this), zone);
|
| +}
|
| +
|
| +
|
| +void RegExpCharacterClass::AppendToText(RegExpText* text, Zone* zone) {
|
| + text->AddElement(TextElement::CharClass(this), zone);
|
| +}
|
| +
|
| +
|
| +void RegExpText::AppendToText(RegExpText* text, Zone* zone) {
|
| + for (int i = 0; i < elements()->length(); i++)
|
| + text->AddElement(elements()->at(i), zone);
|
| +}
|
| +
|
| +
|
| +TextElement TextElement::Atom(RegExpAtom* atom) {
|
| + return TextElement(ATOM, atom);
|
| +}
|
| +
|
| +
|
| +TextElement TextElement::CharClass(RegExpCharacterClass* char_class) {
|
| + return TextElement(CHAR_CLASS, char_class);
|
| +}
|
| +
|
| +
|
| +int TextElement::length() const {
|
| + switch (text_type()) {
|
| + case ATOM:
|
| + return atom()->length();
|
| +
|
| + case CHAR_CLASS:
|
| + return 1;
|
| + }
|
| + UNREACHABLE();
|
| + return 0;
|
| +}
|
| +
|
| +
|
| +DispatchTable* ChoiceNode::GetTable(bool ignore_case) {
|
| + if (table_ == NULL) {
|
| + table_ = new(zone()) DispatchTable(zone());
|
| + DispatchTableConstructor cons(table_, ignore_case, zone());
|
| + cons.BuildTable(this);
|
| + }
|
| + return table_;
|
| +}
|
| +
|
| +
|
| +class FrequencyCollator {
|
| + public:
|
| + FrequencyCollator() : total_samples_(0) {
|
| + for (int i = 0; i < RegExpMacroAssembler::kTableSize; i++) {
|
| + frequencies_[i] = CharacterFrequency(i);
|
| + }
|
| + }
|
| +
|
| + void CountCharacter(int character) {
|
| + int index = (character & RegExpMacroAssembler::kTableMask);
|
| + frequencies_[index].Increment();
|
| + total_samples_++;
|
| + }
|
| +
|
| + // Does not measure in percent, but rather per-128 (the table size from the
|
| + // regexp macro assembler).
|
| + int Frequency(int in_character) {
|
| + DCHECK((in_character & RegExpMacroAssembler::kTableMask) == in_character);
|
| + if (total_samples_ < 1) return 1; // Division by zero.
|
| + int freq_in_per128 =
|
| + (frequencies_[in_character].counter() * 128) / total_samples_;
|
| + return freq_in_per128;
|
| + }
|
| +
|
| + private:
|
| + class CharacterFrequency {
|
| + public:
|
| + CharacterFrequency() : counter_(0), character_(-1) { }
|
| + explicit CharacterFrequency(int character)
|
| + : counter_(0), character_(character) { }
|
| +
|
| + void Increment() { counter_++; }
|
| + int counter() { return counter_; }
|
| + int character() { return character_; }
|
| +
|
| + private:
|
| + int counter_;
|
| + int character_;
|
| + };
|
| +
|
| +
|
| + private:
|
| + CharacterFrequency frequencies_[RegExpMacroAssembler::kTableSize];
|
| + int total_samples_;
|
| +};
|
| +
|
| +
|
| +class RegExpCompiler {
|
| + public:
|
| + RegExpCompiler(int capture_count, bool ignore_case, bool is_one_byte,
|
| + Zone* zone);
|
| +
|
| + int AllocateRegister() {
|
| + if (next_register_ >= RegExpMacroAssembler::kMaxRegister) {
|
| + reg_exp_too_big_ = true;
|
| + return next_register_;
|
| + }
|
| + return next_register_++;
|
| + }
|
| +
|
| + RegExpEngine::CompilationResult Assemble(RegExpMacroAssembler* assembler,
|
| + RegExpNode* start,
|
| + int capture_count,
|
| + Handle<String> pattern);
|
| +
|
| + inline void AddWork(RegExpNode* node) { work_list_->Add(node); }
|
| +
|
| + static const int kImplementationOffset = 0;
|
| + static const int kNumberOfRegistersOffset = 0;
|
| + static const int kCodeOffset = 1;
|
| +
|
| + RegExpMacroAssembler* macro_assembler() { return macro_assembler_; }
|
| + EndNode* accept() { return accept_; }
|
| +
|
| + static const int kMaxRecursion = 100;
|
| + inline int recursion_depth() { return recursion_depth_; }
|
| + inline void IncrementRecursionDepth() { recursion_depth_++; }
|
| + inline void DecrementRecursionDepth() { recursion_depth_--; }
|
| +
|
| + void SetRegExpTooBig() { reg_exp_too_big_ = true; }
|
| +
|
| + inline bool ignore_case() { return ignore_case_; }
|
| + inline bool one_byte() { return one_byte_; }
|
| + FrequencyCollator* frequency_collator() { return &frequency_collator_; }
|
| +
|
| + int current_expansion_factor() { return current_expansion_factor_; }
|
| + void set_current_expansion_factor(int value) {
|
| + current_expansion_factor_ = value;
|
| + }
|
| +
|
| + Zone* zone() const { return zone_; }
|
| +
|
| + static const int kNoRegister = -1;
|
| +
|
| + private:
|
| + EndNode* accept_;
|
| + int next_register_;
|
| + List<RegExpNode*>* work_list_;
|
| + int recursion_depth_;
|
| + RegExpMacroAssembler* macro_assembler_;
|
| + bool ignore_case_;
|
| + bool one_byte_;
|
| + bool reg_exp_too_big_;
|
| + int current_expansion_factor_;
|
| + FrequencyCollator frequency_collator_;
|
| + Zone* zone_;
|
| +};
|
| +
|
| +
|
| +class RecursionCheck {
|
| + public:
|
| + explicit RecursionCheck(RegExpCompiler* compiler) : compiler_(compiler) {
|
| + compiler->IncrementRecursionDepth();
|
| + }
|
| + ~RecursionCheck() { compiler_->DecrementRecursionDepth(); }
|
| + private:
|
| + RegExpCompiler* compiler_;
|
| +};
|
| +
|
| +
|
| +static RegExpEngine::CompilationResult IrregexpRegExpTooBig(Isolate* isolate) {
|
| + return RegExpEngine::CompilationResult(isolate, "RegExp too big");
|
| +}
|
| +
|
| +
|
| +// Attempts to compile the regexp using an Irregexp code generator. Returns
|
| +// a fixed array or a null handle depending on whether it succeeded.
|
| +RegExpCompiler::RegExpCompiler(int capture_count, bool ignore_case,
|
| + bool one_byte, Zone* zone)
|
| + : next_register_(2 * (capture_count + 1)),
|
| + work_list_(NULL),
|
| + recursion_depth_(0),
|
| + ignore_case_(ignore_case),
|
| + one_byte_(one_byte),
|
| + reg_exp_too_big_(false),
|
| + current_expansion_factor_(1),
|
| + frequency_collator_(),
|
| + zone_(zone) {
|
| + accept_ = new(zone) EndNode(EndNode::ACCEPT, zone);
|
| + DCHECK(next_register_ - 1 <= RegExpMacroAssembler::kMaxRegister);
|
| +}
|
| +
|
| +
|
| +RegExpEngine::CompilationResult RegExpCompiler::Assemble(
|
| + RegExpMacroAssembler* macro_assembler,
|
| + RegExpNode* start,
|
| + int capture_count,
|
| + Handle<String> pattern) {
|
| + Heap* heap = pattern->GetHeap();
|
| +
|
| + bool use_slow_safe_regexp_compiler = false;
|
| + if (heap->total_regexp_code_generated() >
|
| + RegExpImpl::kRegWxpCompiledLimit &&
|
| + heap->isolate()->memory_allocator()->SizeExecutable() >
|
| + RegExpImpl::kRegExpExecutableMemoryLimit) {
|
| + use_slow_safe_regexp_compiler = true;
|
| + }
|
| +
|
| + macro_assembler->set_slow_safe(use_slow_safe_regexp_compiler);
|
| +
|
| +#ifdef DEBUG
|
| + if (FLAG_trace_regexp_assembler)
|
| + macro_assembler_ = new RegExpMacroAssemblerTracer(macro_assembler);
|
| + else
|
| +#endif
|
| + macro_assembler_ = macro_assembler;
|
| +
|
| + List <RegExpNode*> work_list(0);
|
| + work_list_ = &work_list;
|
| + Label fail;
|
| + macro_assembler_->PushBacktrack(&fail);
|
| + Trace new_trace;
|
| + start->Emit(this, &new_trace);
|
| + macro_assembler_->Bind(&fail);
|
| + macro_assembler_->Fail();
|
| + while (!work_list.is_empty()) {
|
| + work_list.RemoveLast()->Emit(this, &new_trace);
|
| + }
|
| + if (reg_exp_too_big_) return IrregexpRegExpTooBig(zone_->isolate());
|
| +
|
| + Handle<HeapObject> code = macro_assembler_->GetCode(pattern);
|
| + heap->IncreaseTotalRegexpCodeGenerated(code->Size());
|
| + work_list_ = NULL;
|
| +#ifdef DEBUG
|
| + if (FLAG_print_code) {
|
| + CodeTracer::Scope trace_scope(heap->isolate()->GetCodeTracer());
|
| + OFStream os(trace_scope.file());
|
| + Handle<Code>::cast(code)->Disassemble(pattern->ToCString().get(), os);
|
| + }
|
| + if (FLAG_trace_regexp_assembler) {
|
| + delete macro_assembler_;
|
| + }
|
| +#endif
|
| + return RegExpEngine::CompilationResult(*code, next_register_);
|
| +}
|
| +
|
| +
|
| +bool Trace::DeferredAction::Mentions(int that) {
|
| + if (action_type() == ActionNode::CLEAR_CAPTURES) {
|
| + Interval range = static_cast<DeferredClearCaptures*>(this)->range();
|
| + return range.Contains(that);
|
| + } else {
|
| + return reg() == that;
|
| + }
|
| +}
|
| +
|
| +
|
| +bool Trace::mentions_reg(int reg) {
|
| + for (DeferredAction* action = actions_;
|
| + action != NULL;
|
| + action = action->next()) {
|
| + if (action->Mentions(reg))
|
| + return true;
|
| + }
|
| + return false;
|
| +}
|
| +
|
| +
|
| +bool Trace::GetStoredPosition(int reg, int* cp_offset) {
|
| + DCHECK_EQ(0, *cp_offset);
|
| + for (DeferredAction* action = actions_;
|
| + action != NULL;
|
| + action = action->next()) {
|
| + if (action->Mentions(reg)) {
|
| + if (action->action_type() == ActionNode::STORE_POSITION) {
|
| + *cp_offset = static_cast<DeferredCapture*>(action)->cp_offset();
|
| + return true;
|
| + } else {
|
| + return false;
|
| + }
|
| + }
|
| + }
|
| + return false;
|
| +}
|
| +
|
| +
|
| +int Trace::FindAffectedRegisters(OutSet* affected_registers,
|
| + Zone* zone) {
|
| + int max_register = RegExpCompiler::kNoRegister;
|
| + for (DeferredAction* action = actions_;
|
| + action != NULL;
|
| + action = action->next()) {
|
| + if (action->action_type() == ActionNode::CLEAR_CAPTURES) {
|
| + Interval range = static_cast<DeferredClearCaptures*>(action)->range();
|
| + for (int i = range.from(); i <= range.to(); i++)
|
| + affected_registers->Set(i, zone);
|
| + if (range.to() > max_register) max_register = range.to();
|
| + } else {
|
| + affected_registers->Set(action->reg(), zone);
|
| + if (action->reg() > max_register) max_register = action->reg();
|
| + }
|
| + }
|
| + return max_register;
|
| +}
|
| +
|
| +
|
| +void Trace::RestoreAffectedRegisters(RegExpMacroAssembler* assembler,
|
| + int max_register,
|
| + const OutSet& registers_to_pop,
|
| + const OutSet& registers_to_clear) {
|
| + for (int reg = max_register; reg >= 0; reg--) {
|
| + if (registers_to_pop.Get(reg)) {
|
| + assembler->PopRegister(reg);
|
| + } else if (registers_to_clear.Get(reg)) {
|
| + int clear_to = reg;
|
| + while (reg > 0 && registers_to_clear.Get(reg - 1)) {
|
| + reg--;
|
| + }
|
| + assembler->ClearRegisters(reg, clear_to);
|
| + }
|
| + }
|
| +}
|
| +
|
| +
|
| +void Trace::PerformDeferredActions(RegExpMacroAssembler* assembler,
|
| + int max_register,
|
| + const OutSet& affected_registers,
|
| + OutSet* registers_to_pop,
|
| + OutSet* registers_to_clear,
|
| + Zone* zone) {
|
| + // The "+1" is to avoid a push_limit of zero if stack_limit_slack() is 1.
|
| + const int push_limit = (assembler->stack_limit_slack() + 1) / 2;
|
| +
|
| + // Count pushes performed to force a stack limit check occasionally.
|
| + int pushes = 0;
|
| +
|
| + for (int reg = 0; reg <= max_register; reg++) {
|
| + if (!affected_registers.Get(reg)) {
|
| + continue;
|
| + }
|
| +
|
| + // The chronologically first deferred action in the trace
|
| + // is used to infer the action needed to restore a register
|
| + // to its previous state (or not, if it's safe to ignore it).
|
| + enum DeferredActionUndoType { IGNORE, RESTORE, CLEAR };
|
| + DeferredActionUndoType undo_action = IGNORE;
|
| +
|
| + int value = 0;
|
| + bool absolute = false;
|
| + bool clear = false;
|
| + int store_position = -1;
|
| + // This is a little tricky because we are scanning the actions in reverse
|
| + // historical order (newest first).
|
| + for (DeferredAction* action = actions_;
|
| + action != NULL;
|
| + action = action->next()) {
|
| + if (action->Mentions(reg)) {
|
| + switch (action->action_type()) {
|
| + case ActionNode::SET_REGISTER: {
|
| + Trace::DeferredSetRegister* psr =
|
| + static_cast<Trace::DeferredSetRegister*>(action);
|
| + if (!absolute) {
|
| + value += psr->value();
|
| + absolute = true;
|
| + }
|
| + // SET_REGISTER is currently only used for newly introduced loop
|
| + // counters. They can have a significant previous value if they
|
| + // occour in a loop. TODO(lrn): Propagate this information, so
|
| + // we can set undo_action to IGNORE if we know there is no value to
|
| + // restore.
|
| + undo_action = RESTORE;
|
| + DCHECK_EQ(store_position, -1);
|
| + DCHECK(!clear);
|
| + break;
|
| + }
|
| + case ActionNode::INCREMENT_REGISTER:
|
| + if (!absolute) {
|
| + value++;
|
| + }
|
| + DCHECK_EQ(store_position, -1);
|
| + DCHECK(!clear);
|
| + undo_action = RESTORE;
|
| + break;
|
| + case ActionNode::STORE_POSITION: {
|
| + Trace::DeferredCapture* pc =
|
| + static_cast<Trace::DeferredCapture*>(action);
|
| + if (!clear && store_position == -1) {
|
| + store_position = pc->cp_offset();
|
| + }
|
| +
|
| + // For captures we know that stores and clears alternate.
|
| + // Other register, are never cleared, and if the occur
|
| + // inside a loop, they might be assigned more than once.
|
| + if (reg <= 1) {
|
| + // Registers zero and one, aka "capture zero", is
|
| + // always set correctly if we succeed. There is no
|
| + // need to undo a setting on backtrack, because we
|
| + // will set it again or fail.
|
| + undo_action = IGNORE;
|
| + } else {
|
| + undo_action = pc->is_capture() ? CLEAR : RESTORE;
|
| + }
|
| + DCHECK(!absolute);
|
| + DCHECK_EQ(value, 0);
|
| + break;
|
| + }
|
| + case ActionNode::CLEAR_CAPTURES: {
|
| + // Since we're scanning in reverse order, if we've already
|
| + // set the position we have to ignore historically earlier
|
| + // clearing operations.
|
| + if (store_position == -1) {
|
| + clear = true;
|
| + }
|
| + undo_action = RESTORE;
|
| + DCHECK(!absolute);
|
| + DCHECK_EQ(value, 0);
|
| + break;
|
| + }
|
| + default:
|
| + UNREACHABLE();
|
| + break;
|
| + }
|
| + }
|
| + }
|
| + // Prepare for the undo-action (e.g., push if it's going to be popped).
|
| + if (undo_action == RESTORE) {
|
| + pushes++;
|
| + RegExpMacroAssembler::StackCheckFlag stack_check =
|
| + RegExpMacroAssembler::kNoStackLimitCheck;
|
| + if (pushes == push_limit) {
|
| + stack_check = RegExpMacroAssembler::kCheckStackLimit;
|
| + pushes = 0;
|
| + }
|
| +
|
| + assembler->PushRegister(reg, stack_check);
|
| + registers_to_pop->Set(reg, zone);
|
| + } else if (undo_action == CLEAR) {
|
| + registers_to_clear->Set(reg, zone);
|
| + }
|
| + // Perform the chronologically last action (or accumulated increment)
|
| + // for the register.
|
| + if (store_position != -1) {
|
| + assembler->WriteCurrentPositionToRegister(reg, store_position);
|
| + } else if (clear) {
|
| + assembler->ClearRegisters(reg, reg);
|
| + } else if (absolute) {
|
| + assembler->SetRegister(reg, value);
|
| + } else if (value != 0) {
|
| + assembler->AdvanceRegister(reg, value);
|
| + }
|
| + }
|
| +}
|
| +
|
| +
|
| +// This is called as we come into a loop choice node and some other tricky
|
| +// nodes. It normalizes the state of the code generator to ensure we can
|
| +// generate generic code.
|
| +void Trace::Flush(RegExpCompiler* compiler, RegExpNode* successor) {
|
| + RegExpMacroAssembler* assembler = compiler->macro_assembler();
|
| +
|
| + DCHECK(!is_trivial());
|
| +
|
| + if (actions_ == NULL && backtrack() == NULL) {
|
| + // Here we just have some deferred cp advances to fix and we are back to
|
| + // a normal situation. We may also have to forget some information gained
|
| + // through a quick check that was already performed.
|
| + if (cp_offset_ != 0) assembler->AdvanceCurrentPosition(cp_offset_);
|
| + // Create a new trivial state and generate the node with that.
|
| + Trace new_state;
|
| + successor->Emit(compiler, &new_state);
|
| + return;
|
| + }
|
| +
|
| + // Generate deferred actions here along with code to undo them again.
|
| + OutSet affected_registers;
|
| +
|
| + if (backtrack() != NULL) {
|
| + // Here we have a concrete backtrack location. These are set up by choice
|
| + // nodes and so they indicate that we have a deferred save of the current
|
| + // position which we may need to emit here.
|
| + assembler->PushCurrentPosition();
|
| + }
|
| +
|
| + int max_register = FindAffectedRegisters(&affected_registers,
|
| + compiler->zone());
|
| + OutSet registers_to_pop;
|
| + OutSet registers_to_clear;
|
| + PerformDeferredActions(assembler,
|
| + max_register,
|
| + affected_registers,
|
| + ®isters_to_pop,
|
| + ®isters_to_clear,
|
| + compiler->zone());
|
| + if (cp_offset_ != 0) {
|
| + assembler->AdvanceCurrentPosition(cp_offset_);
|
| + }
|
| +
|
| + // Create a new trivial state and generate the node with that.
|
| + Label undo;
|
| + assembler->PushBacktrack(&undo);
|
| + Trace new_state;
|
| + successor->Emit(compiler, &new_state);
|
| +
|
| + // On backtrack we need to restore state.
|
| + assembler->Bind(&undo);
|
| + RestoreAffectedRegisters(assembler,
|
| + max_register,
|
| + registers_to_pop,
|
| + registers_to_clear);
|
| + if (backtrack() == NULL) {
|
| + assembler->Backtrack();
|
| + } else {
|
| + assembler->PopCurrentPosition();
|
| + assembler->GoTo(backtrack());
|
| + }
|
| +}
|
| +
|
| +
|
| +void NegativeSubmatchSuccess::Emit(RegExpCompiler* compiler, Trace* trace) {
|
| + RegExpMacroAssembler* assembler = compiler->macro_assembler();
|
| +
|
| + // Omit flushing the trace. We discard the entire stack frame anyway.
|
| +
|
| + if (!label()->is_bound()) {
|
| + // We are completely independent of the trace, since we ignore it,
|
| + // so this code can be used as the generic version.
|
| + assembler->Bind(label());
|
| + }
|
| +
|
| + // Throw away everything on the backtrack stack since the start
|
| + // of the negative submatch and restore the character position.
|
| + assembler->ReadCurrentPositionFromRegister(current_position_register_);
|
| + assembler->ReadStackPointerFromRegister(stack_pointer_register_);
|
| + if (clear_capture_count_ > 0) {
|
| + // Clear any captures that might have been performed during the success
|
| + // of the body of the negative look-ahead.
|
| + int clear_capture_end = clear_capture_start_ + clear_capture_count_ - 1;
|
| + assembler->ClearRegisters(clear_capture_start_, clear_capture_end);
|
| + }
|
| + // Now that we have unwound the stack we find at the top of the stack the
|
| + // backtrack that the BeginSubmatch node got.
|
| + assembler->Backtrack();
|
| +}
|
| +
|
| +
|
| +void EndNode::Emit(RegExpCompiler* compiler, Trace* trace) {
|
| + if (!trace->is_trivial()) {
|
| + trace->Flush(compiler, this);
|
| + return;
|
| + }
|
| + RegExpMacroAssembler* assembler = compiler->macro_assembler();
|
| + if (!label()->is_bound()) {
|
| + assembler->Bind(label());
|
| + }
|
| + switch (action_) {
|
| + case ACCEPT:
|
| + assembler->Succeed();
|
| + return;
|
| + case BACKTRACK:
|
| + assembler->GoTo(trace->backtrack());
|
| + return;
|
| + case NEGATIVE_SUBMATCH_SUCCESS:
|
| + // This case is handled in a different virtual method.
|
| + UNREACHABLE();
|
| + }
|
| + UNIMPLEMENTED();
|
| +}
|
| +
|
| +
|
| +void GuardedAlternative::AddGuard(Guard* guard, Zone* zone) {
|
| + if (guards_ == NULL)
|
| + guards_ = new(zone) ZoneList<Guard*>(1, zone);
|
| + guards_->Add(guard, zone);
|
| +}
|
| +
|
| +
|
| +ActionNode* ActionNode::SetRegister(int reg,
|
| + int val,
|
| + RegExpNode* on_success) {
|
| + ActionNode* result =
|
| + new(on_success->zone()) ActionNode(SET_REGISTER, on_success);
|
| + result->data_.u_store_register.reg = reg;
|
| + result->data_.u_store_register.value = val;
|
| + return result;
|
| +}
|
| +
|
| +
|
| +ActionNode* ActionNode::IncrementRegister(int reg, RegExpNode* on_success) {
|
| + ActionNode* result =
|
| + new(on_success->zone()) ActionNode(INCREMENT_REGISTER, on_success);
|
| + result->data_.u_increment_register.reg = reg;
|
| + return result;
|
| +}
|
| +
|
| +
|
| +ActionNode* ActionNode::StorePosition(int reg,
|
| + bool is_capture,
|
| + RegExpNode* on_success) {
|
| + ActionNode* result =
|
| + new(on_success->zone()) ActionNode(STORE_POSITION, on_success);
|
| + result->data_.u_position_register.reg = reg;
|
| + result->data_.u_position_register.is_capture = is_capture;
|
| + return result;
|
| +}
|
| +
|
| +
|
| +ActionNode* ActionNode::ClearCaptures(Interval range,
|
| + RegExpNode* on_success) {
|
| + ActionNode* result =
|
| + new(on_success->zone()) ActionNode(CLEAR_CAPTURES, on_success);
|
| + result->data_.u_clear_captures.range_from = range.from();
|
| + result->data_.u_clear_captures.range_to = range.to();
|
| + return result;
|
| +}
|
| +
|
| +
|
| +ActionNode* ActionNode::BeginSubmatch(int stack_reg,
|
| + int position_reg,
|
| + RegExpNode* on_success) {
|
| + ActionNode* result =
|
| + new(on_success->zone()) ActionNode(BEGIN_SUBMATCH, on_success);
|
| + result->data_.u_submatch.stack_pointer_register = stack_reg;
|
| + result->data_.u_submatch.current_position_register = position_reg;
|
| + return result;
|
| +}
|
| +
|
| +
|
| +ActionNode* ActionNode::PositiveSubmatchSuccess(int stack_reg,
|
| + int position_reg,
|
| + int clear_register_count,
|
| + int clear_register_from,
|
| + RegExpNode* on_success) {
|
| + ActionNode* result =
|
| + new(on_success->zone()) ActionNode(POSITIVE_SUBMATCH_SUCCESS, on_success);
|
| + result->data_.u_submatch.stack_pointer_register = stack_reg;
|
| + result->data_.u_submatch.current_position_register = position_reg;
|
| + result->data_.u_submatch.clear_register_count = clear_register_count;
|
| + result->data_.u_submatch.clear_register_from = clear_register_from;
|
| + return result;
|
| +}
|
| +
|
| +
|
| +ActionNode* ActionNode::EmptyMatchCheck(int start_register,
|
| + int repetition_register,
|
| + int repetition_limit,
|
| + RegExpNode* on_success) {
|
| + ActionNode* result =
|
| + new(on_success->zone()) ActionNode(EMPTY_MATCH_CHECK, on_success);
|
| + result->data_.u_empty_match_check.start_register = start_register;
|
| + result->data_.u_empty_match_check.repetition_register = repetition_register;
|
| + result->data_.u_empty_match_check.repetition_limit = repetition_limit;
|
| + return result;
|
| +}
|
| +
|
| +
|
| +#define DEFINE_ACCEPT(Type) \
|
| + void Type##Node::Accept(NodeVisitor* visitor) { \
|
| + visitor->Visit##Type(this); \
|
| + }
|
| +FOR_EACH_NODE_TYPE(DEFINE_ACCEPT)
|
| +#undef DEFINE_ACCEPT
|
| +
|
| +
|
| +void LoopChoiceNode::Accept(NodeVisitor* visitor) {
|
| + visitor->VisitLoopChoice(this);
|
| +}
|
| +
|
| +
|
| +// -------------------------------------------------------------------
|
| +// Emit code.
|
| +
|
| +
|
| +void ChoiceNode::GenerateGuard(RegExpMacroAssembler* macro_assembler,
|
| + Guard* guard,
|
| + Trace* trace) {
|
| + switch (guard->op()) {
|
| + case Guard::LT:
|
| + DCHECK(!trace->mentions_reg(guard->reg()));
|
| + macro_assembler->IfRegisterGE(guard->reg(),
|
| + guard->value(),
|
| + trace->backtrack());
|
| + break;
|
| + case Guard::GEQ:
|
| + DCHECK(!trace->mentions_reg(guard->reg()));
|
| + macro_assembler->IfRegisterLT(guard->reg(),
|
| + guard->value(),
|
| + trace->backtrack());
|
| + break;
|
| + }
|
| +}
|
| +
|
| +
|
| +// Returns the number of characters in the equivalence class, omitting those
|
| +// that cannot occur in the source string because it is ASCII.
|
| +static int GetCaseIndependentLetters(Isolate* isolate, uc16 character,
|
| + bool one_byte_subject,
|
| + unibrow::uchar* letters) {
|
| + int length =
|
| + isolate->jsregexp_uncanonicalize()->get(character, '\0', letters);
|
| + // Unibrow returns 0 or 1 for characters where case independence is
|
| + // trivial.
|
| + if (length == 0) {
|
| + letters[0] = character;
|
| + length = 1;
|
| + }
|
| + if (!one_byte_subject || character <= String::kMaxOneByteCharCode) {
|
| + return length;
|
| + }
|
| +
|
| + // The standard requires that non-ASCII characters cannot have ASCII
|
| + // character codes in their equivalence class.
|
| + // TODO(dcarney): issue 3550 this is not actually true for Latin1 anymore,
|
| + // is it? For example, \u00C5 is equivalent to \u212B.
|
| + return 0;
|
| +}
|
| +
|
| +
|
| +static inline bool EmitSimpleCharacter(Isolate* isolate,
|
| + RegExpCompiler* compiler,
|
| + uc16 c,
|
| + Label* on_failure,
|
| + int cp_offset,
|
| + bool check,
|
| + bool preloaded) {
|
| + RegExpMacroAssembler* assembler = compiler->macro_assembler();
|
| + bool bound_checked = false;
|
| + if (!preloaded) {
|
| + assembler->LoadCurrentCharacter(
|
| + cp_offset,
|
| + on_failure,
|
| + check);
|
| + bound_checked = true;
|
| + }
|
| + assembler->CheckNotCharacter(c, on_failure);
|
| + return bound_checked;
|
| +}
|
| +
|
| +
|
| +// Only emits non-letters (things that don't have case). Only used for case
|
| +// independent matches.
|
| +static inline bool EmitAtomNonLetter(Isolate* isolate,
|
| + RegExpCompiler* compiler,
|
| + uc16 c,
|
| + Label* on_failure,
|
| + int cp_offset,
|
| + bool check,
|
| + bool preloaded) {
|
| + RegExpMacroAssembler* macro_assembler = compiler->macro_assembler();
|
| + bool one_byte = compiler->one_byte();
|
| + unibrow::uchar chars[unibrow::Ecma262UnCanonicalize::kMaxWidth];
|
| + int length = GetCaseIndependentLetters(isolate, c, one_byte, chars);
|
| + if (length < 1) {
|
| + // This can't match. Must be an one-byte subject and a non-one-byte
|
| + // character. We do not need to do anything since the one-byte pass
|
| + // already handled this.
|
| + return false; // Bounds not checked.
|
| + }
|
| + bool checked = false;
|
| + // We handle the length > 1 case in a later pass.
|
| + if (length == 1) {
|
| + if (one_byte && c > String::kMaxOneByteCharCodeU) {
|
| + // Can't match - see above.
|
| + return false; // Bounds not checked.
|
| + }
|
| + if (!preloaded) {
|
| + macro_assembler->LoadCurrentCharacter(cp_offset, on_failure, check);
|
| + checked = check;
|
| + }
|
| + macro_assembler->CheckNotCharacter(c, on_failure);
|
| + }
|
| + return checked;
|
| +}
|
| +
|
| +
|
| +static bool ShortCutEmitCharacterPair(RegExpMacroAssembler* macro_assembler,
|
| + bool one_byte, uc16 c1, uc16 c2,
|
| + Label* on_failure) {
|
| + uc16 char_mask;
|
| + if (one_byte) {
|
| + char_mask = String::kMaxOneByteCharCode;
|
| + } else {
|
| + char_mask = String::kMaxUtf16CodeUnit;
|
| + }
|
| + uc16 exor = c1 ^ c2;
|
| + // Check whether exor has only one bit set.
|
| + if (((exor - 1) & exor) == 0) {
|
| + // If c1 and c2 differ only by one bit.
|
| + // Ecma262UnCanonicalize always gives the highest number last.
|
| + DCHECK(c2 > c1);
|
| + uc16 mask = char_mask ^ exor;
|
| + macro_assembler->CheckNotCharacterAfterAnd(c1, mask, on_failure);
|
| + return true;
|
| + }
|
| + DCHECK(c2 > c1);
|
| + uc16 diff = c2 - c1;
|
| + if (((diff - 1) & diff) == 0 && c1 >= diff) {
|
| + // If the characters differ by 2^n but don't differ by one bit then
|
| + // subtract the difference from the found character, then do the or
|
| + // trick. We avoid the theoretical case where negative numbers are
|
| + // involved in order to simplify code generation.
|
| + uc16 mask = char_mask ^ diff;
|
| + macro_assembler->CheckNotCharacterAfterMinusAnd(c1 - diff,
|
| + diff,
|
| + mask,
|
| + on_failure);
|
| + return true;
|
| + }
|
| + return false;
|
| +}
|
| +
|
| +
|
| +typedef bool EmitCharacterFunction(Isolate* isolate,
|
| + RegExpCompiler* compiler,
|
| + uc16 c,
|
| + Label* on_failure,
|
| + int cp_offset,
|
| + bool check,
|
| + bool preloaded);
|
| +
|
| +// Only emits letters (things that have case). Only used for case independent
|
| +// matches.
|
| +static inline bool EmitAtomLetter(Isolate* isolate,
|
| + RegExpCompiler* compiler,
|
| + uc16 c,
|
| + Label* on_failure,
|
| + int cp_offset,
|
| + bool check,
|
| + bool preloaded) {
|
| + RegExpMacroAssembler* macro_assembler = compiler->macro_assembler();
|
| + bool one_byte = compiler->one_byte();
|
| + unibrow::uchar chars[unibrow::Ecma262UnCanonicalize::kMaxWidth];
|
| + int length = GetCaseIndependentLetters(isolate, c, one_byte, chars);
|
| + if (length <= 1) return false;
|
| + // We may not need to check against the end of the input string
|
| + // if this character lies before a character that matched.
|
| + if (!preloaded) {
|
| + macro_assembler->LoadCurrentCharacter(cp_offset, on_failure, check);
|
| + }
|
| + Label ok;
|
| + DCHECK(unibrow::Ecma262UnCanonicalize::kMaxWidth == 4);
|
| + switch (length) {
|
| + case 2: {
|
| + if (ShortCutEmitCharacterPair(macro_assembler, one_byte, chars[0],
|
| + chars[1], on_failure)) {
|
| + } else {
|
| + macro_assembler->CheckCharacter(chars[0], &ok);
|
| + macro_assembler->CheckNotCharacter(chars[1], on_failure);
|
| + macro_assembler->Bind(&ok);
|
| + }
|
| + break;
|
| + }
|
| + case 4:
|
| + macro_assembler->CheckCharacter(chars[3], &ok);
|
| + // Fall through!
|
| + case 3:
|
| + macro_assembler->CheckCharacter(chars[0], &ok);
|
| + macro_assembler->CheckCharacter(chars[1], &ok);
|
| + macro_assembler->CheckNotCharacter(chars[2], on_failure);
|
| + macro_assembler->Bind(&ok);
|
| + break;
|
| + default:
|
| + UNREACHABLE();
|
| + break;
|
| + }
|
| + return true;
|
| +}
|
| +
|
| +
|
| +static void EmitBoundaryTest(RegExpMacroAssembler* masm,
|
| + int border,
|
| + Label* fall_through,
|
| + Label* above_or_equal,
|
| + Label* below) {
|
| + if (below != fall_through) {
|
| + masm->CheckCharacterLT(border, below);
|
| + if (above_or_equal != fall_through) masm->GoTo(above_or_equal);
|
| + } else {
|
| + masm->CheckCharacterGT(border - 1, above_or_equal);
|
| + }
|
| +}
|
| +
|
| +
|
| +static void EmitDoubleBoundaryTest(RegExpMacroAssembler* masm,
|
| + int first,
|
| + int last,
|
| + Label* fall_through,
|
| + Label* in_range,
|
| + Label* out_of_range) {
|
| + if (in_range == fall_through) {
|
| + if (first == last) {
|
| + masm->CheckNotCharacter(first, out_of_range);
|
| + } else {
|
| + masm->CheckCharacterNotInRange(first, last, out_of_range);
|
| + }
|
| + } else {
|
| + if (first == last) {
|
| + masm->CheckCharacter(first, in_range);
|
| + } else {
|
| + masm->CheckCharacterInRange(first, last, in_range);
|
| + }
|
| + if (out_of_range != fall_through) masm->GoTo(out_of_range);
|
| + }
|
| +}
|
| +
|
| +
|
| +// even_label is for ranges[i] to ranges[i + 1] where i - start_index is even.
|
| +// odd_label is for ranges[i] to ranges[i + 1] where i - start_index is odd.
|
| +static void EmitUseLookupTable(
|
| + RegExpMacroAssembler* masm,
|
| + ZoneList<int>* ranges,
|
| + int start_index,
|
| + int end_index,
|
| + int min_char,
|
| + Label* fall_through,
|
| + Label* even_label,
|
| + Label* odd_label) {
|
| + static const int kSize = RegExpMacroAssembler::kTableSize;
|
| + static const int kMask = RegExpMacroAssembler::kTableMask;
|
| +
|
| + int base = (min_char & ~kMask);
|
| + USE(base);
|
| +
|
| + // Assert that everything is on one kTableSize page.
|
| + for (int i = start_index; i <= end_index; i++) {
|
| + DCHECK_EQ(ranges->at(i) & ~kMask, base);
|
| + }
|
| + DCHECK(start_index == 0 || (ranges->at(start_index - 1) & ~kMask) <= base);
|
| +
|
| + char templ[kSize];
|
| + Label* on_bit_set;
|
| + Label* on_bit_clear;
|
| + int bit;
|
| + if (even_label == fall_through) {
|
| + on_bit_set = odd_label;
|
| + on_bit_clear = even_label;
|
| + bit = 1;
|
| + } else {
|
| + on_bit_set = even_label;
|
| + on_bit_clear = odd_label;
|
| + bit = 0;
|
| + }
|
| + for (int i = 0; i < (ranges->at(start_index) & kMask) && i < kSize; i++) {
|
| + templ[i] = bit;
|
| + }
|
| + int j = 0;
|
| + bit ^= 1;
|
| + for (int i = start_index; i < end_index; i++) {
|
| + for (j = (ranges->at(i) & kMask); j < (ranges->at(i + 1) & kMask); j++) {
|
| + templ[j] = bit;
|
| + }
|
| + bit ^= 1;
|
| + }
|
| + for (int i = j; i < kSize; i++) {
|
| + templ[i] = bit;
|
| + }
|
| + Factory* factory = masm->zone()->isolate()->factory();
|
| + // TODO(erikcorry): Cache these.
|
| + Handle<ByteArray> ba = factory->NewByteArray(kSize, TENURED);
|
| + for (int i = 0; i < kSize; i++) {
|
| + ba->set(i, templ[i]);
|
| + }
|
| + masm->CheckBitInTable(ba, on_bit_set);
|
| + if (on_bit_clear != fall_through) masm->GoTo(on_bit_clear);
|
| +}
|
| +
|
| +
|
| +static void CutOutRange(RegExpMacroAssembler* masm,
|
| + ZoneList<int>* ranges,
|
| + int start_index,
|
| + int end_index,
|
| + int cut_index,
|
| + Label* even_label,
|
| + Label* odd_label) {
|
| + bool odd = (((cut_index - start_index) & 1) == 1);
|
| + Label* in_range_label = odd ? odd_label : even_label;
|
| + Label dummy;
|
| + EmitDoubleBoundaryTest(masm,
|
| + ranges->at(cut_index),
|
| + ranges->at(cut_index + 1) - 1,
|
| + &dummy,
|
| + in_range_label,
|
| + &dummy);
|
| + DCHECK(!dummy.is_linked());
|
| + // Cut out the single range by rewriting the array. This creates a new
|
| + // range that is a merger of the two ranges on either side of the one we
|
| + // are cutting out. The oddity of the labels is preserved.
|
| + for (int j = cut_index; j > start_index; j--) {
|
| + ranges->at(j) = ranges->at(j - 1);
|
| + }
|
| + for (int j = cut_index + 1; j < end_index; j++) {
|
| + ranges->at(j) = ranges->at(j + 1);
|
| + }
|
| +}
|
| +
|
| +
|
| +// Unicode case. Split the search space into kSize spaces that are handled
|
| +// with recursion.
|
| +static void SplitSearchSpace(ZoneList<int>* ranges,
|
| + int start_index,
|
| + int end_index,
|
| + int* new_start_index,
|
| + int* new_end_index,
|
| + int* border) {
|
| + static const int kSize = RegExpMacroAssembler::kTableSize;
|
| + static const int kMask = RegExpMacroAssembler::kTableMask;
|
| +
|
| + int first = ranges->at(start_index);
|
| + int last = ranges->at(end_index) - 1;
|
| +
|
| + *new_start_index = start_index;
|
| + *border = (ranges->at(start_index) & ~kMask) + kSize;
|
| + while (*new_start_index < end_index) {
|
| + if (ranges->at(*new_start_index) > *border) break;
|
| + (*new_start_index)++;
|
| + }
|
| + // new_start_index is the index of the first edge that is beyond the
|
| + // current kSize space.
|
| +
|
| + // For very large search spaces we do a binary chop search of the non-Latin1
|
| + // space instead of just going to the end of the current kSize space. The
|
| + // heuristics are complicated a little by the fact that any 128-character
|
| + // encoding space can be quickly tested with a table lookup, so we don't
|
| + // wish to do binary chop search at a smaller granularity than that. A
|
| + // 128-character space can take up a lot of space in the ranges array if,
|
| + // for example, we only want to match every second character (eg. the lower
|
| + // case characters on some Unicode pages).
|
| + int binary_chop_index = (end_index + start_index) / 2;
|
| + // The first test ensures that we get to the code that handles the Latin1
|
| + // range with a single not-taken branch, speeding up this important
|
| + // character range (even non-Latin1 charset-based text has spaces and
|
| + // punctuation).
|
| + if (*border - 1 > String::kMaxOneByteCharCode && // Latin1 case.
|
| + end_index - start_index > (*new_start_index - start_index) * 2 &&
|
| + last - first > kSize * 2 && binary_chop_index > *new_start_index &&
|
| + ranges->at(binary_chop_index) >= first + 2 * kSize) {
|
| + int scan_forward_for_section_border = binary_chop_index;;
|
| + int new_border = (ranges->at(binary_chop_index) | kMask) + 1;
|
| +
|
| + while (scan_forward_for_section_border < end_index) {
|
| + if (ranges->at(scan_forward_for_section_border) > new_border) {
|
| + *new_start_index = scan_forward_for_section_border;
|
| + *border = new_border;
|
| + break;
|
| + }
|
| + scan_forward_for_section_border++;
|
| + }
|
| + }
|
| +
|
| + DCHECK(*new_start_index > start_index);
|
| + *new_end_index = *new_start_index - 1;
|
| + if (ranges->at(*new_end_index) == *border) {
|
| + (*new_end_index)--;
|
| + }
|
| + if (*border >= ranges->at(end_index)) {
|
| + *border = ranges->at(end_index);
|
| + *new_start_index = end_index; // Won't be used.
|
| + *new_end_index = end_index - 1;
|
| + }
|
| +}
|
| +
|
| +
|
| +// Gets a series of segment boundaries representing a character class. If the
|
| +// character is in the range between an even and an odd boundary (counting from
|
| +// start_index) then go to even_label, otherwise go to odd_label. We already
|
| +// know that the character is in the range of min_char to max_char inclusive.
|
| +// Either label can be NULL indicating backtracking. Either label can also be
|
| +// equal to the fall_through label.
|
| +static void GenerateBranches(RegExpMacroAssembler* masm,
|
| + ZoneList<int>* ranges,
|
| + int start_index,
|
| + int end_index,
|
| + uc16 min_char,
|
| + uc16 max_char,
|
| + Label* fall_through,
|
| + Label* even_label,
|
| + Label* odd_label) {
|
| + int first = ranges->at(start_index);
|
| + int last = ranges->at(end_index) - 1;
|
| +
|
| + DCHECK_LT(min_char, first);
|
| +
|
| + // Just need to test if the character is before or on-or-after
|
| + // a particular character.
|
| + if (start_index == end_index) {
|
| + EmitBoundaryTest(masm, first, fall_through, even_label, odd_label);
|
| + return;
|
| + }
|
| +
|
| + // Another almost trivial case: There is one interval in the middle that is
|
| + // different from the end intervals.
|
| + if (start_index + 1 == end_index) {
|
| + EmitDoubleBoundaryTest(
|
| + masm, first, last, fall_through, even_label, odd_label);
|
| + return;
|
| + }
|
| +
|
| + // It's not worth using table lookup if there are very few intervals in the
|
| + // character class.
|
| + if (end_index - start_index <= 6) {
|
| + // It is faster to test for individual characters, so we look for those
|
| + // first, then try arbitrary ranges in the second round.
|
| + static int kNoCutIndex = -1;
|
| + int cut = kNoCutIndex;
|
| + for (int i = start_index; i < end_index; i++) {
|
| + if (ranges->at(i) == ranges->at(i + 1) - 1) {
|
| + cut = i;
|
| + break;
|
| + }
|
| + }
|
| + if (cut == kNoCutIndex) cut = start_index;
|
| + CutOutRange(
|
| + masm, ranges, start_index, end_index, cut, even_label, odd_label);
|
| + DCHECK_GE(end_index - start_index, 2);
|
| + GenerateBranches(masm,
|
| + ranges,
|
| + start_index + 1,
|
| + end_index - 1,
|
| + min_char,
|
| + max_char,
|
| + fall_through,
|
| + even_label,
|
| + odd_label);
|
| + return;
|
| + }
|
| +
|
| + // If there are a lot of intervals in the regexp, then we will use tables to
|
| + // determine whether the character is inside or outside the character class.
|
| + static const int kBits = RegExpMacroAssembler::kTableSizeBits;
|
| +
|
| + if ((max_char >> kBits) == (min_char >> kBits)) {
|
| + EmitUseLookupTable(masm,
|
| + ranges,
|
| + start_index,
|
| + end_index,
|
| + min_char,
|
| + fall_through,
|
| + even_label,
|
| + odd_label);
|
| + return;
|
| + }
|
| +
|
| + if ((min_char >> kBits) != (first >> kBits)) {
|
| + masm->CheckCharacterLT(first, odd_label);
|
| + GenerateBranches(masm,
|
| + ranges,
|
| + start_index + 1,
|
| + end_index,
|
| + first,
|
| + max_char,
|
| + fall_through,
|
| + odd_label,
|
| + even_label);
|
| + return;
|
| + }
|
| +
|
| + int new_start_index = 0;
|
| + int new_end_index = 0;
|
| + int border = 0;
|
| +
|
| + SplitSearchSpace(ranges,
|
| + start_index,
|
| + end_index,
|
| + &new_start_index,
|
| + &new_end_index,
|
| + &border);
|
| +
|
| + Label handle_rest;
|
| + Label* above = &handle_rest;
|
| + if (border == last + 1) {
|
| + // We didn't find any section that started after the limit, so everything
|
| + // above the border is one of the terminal labels.
|
| + above = (end_index & 1) != (start_index & 1) ? odd_label : even_label;
|
| + DCHECK(new_end_index == end_index - 1);
|
| + }
|
| +
|
| + DCHECK_LE(start_index, new_end_index);
|
| + DCHECK_LE(new_start_index, end_index);
|
| + DCHECK_LT(start_index, new_start_index);
|
| + DCHECK_LT(new_end_index, end_index);
|
| + DCHECK(new_end_index + 1 == new_start_index ||
|
| + (new_end_index + 2 == new_start_index &&
|
| + border == ranges->at(new_end_index + 1)));
|
| + DCHECK_LT(min_char, border - 1);
|
| + DCHECK_LT(border, max_char);
|
| + DCHECK_LT(ranges->at(new_end_index), border);
|
| + DCHECK(border < ranges->at(new_start_index) ||
|
| + (border == ranges->at(new_start_index) &&
|
| + new_start_index == end_index &&
|
| + new_end_index == end_index - 1 &&
|
| + border == last + 1));
|
| + DCHECK(new_start_index == 0 || border >= ranges->at(new_start_index - 1));
|
| +
|
| + masm->CheckCharacterGT(border - 1, above);
|
| + Label dummy;
|
| + GenerateBranches(masm,
|
| + ranges,
|
| + start_index,
|
| + new_end_index,
|
| + min_char,
|
| + border - 1,
|
| + &dummy,
|
| + even_label,
|
| + odd_label);
|
| + if (handle_rest.is_linked()) {
|
| + masm->Bind(&handle_rest);
|
| + bool flip = (new_start_index & 1) != (start_index & 1);
|
| + GenerateBranches(masm,
|
| + ranges,
|
| + new_start_index,
|
| + end_index,
|
| + border,
|
| + max_char,
|
| + &dummy,
|
| + flip ? odd_label : even_label,
|
| + flip ? even_label : odd_label);
|
| + }
|
| +}
|
| +
|
| +
|
| +static void EmitCharClass(RegExpMacroAssembler* macro_assembler,
|
| + RegExpCharacterClass* cc, bool one_byte,
|
| + Label* on_failure, int cp_offset, bool check_offset,
|
| + bool preloaded, Zone* zone) {
|
| + ZoneList<CharacterRange>* ranges = cc->ranges(zone);
|
| + if (!CharacterRange::IsCanonical(ranges)) {
|
| + CharacterRange::Canonicalize(ranges);
|
| + }
|
| +
|
| + int max_char;
|
| + if (one_byte) {
|
| + max_char = String::kMaxOneByteCharCode;
|
| + } else {
|
| + max_char = String::kMaxUtf16CodeUnit;
|
| + }
|
| +
|
| + int range_count = ranges->length();
|
| +
|
| + int last_valid_range = range_count - 1;
|
| + while (last_valid_range >= 0) {
|
| + CharacterRange& range = ranges->at(last_valid_range);
|
| + if (range.from() <= max_char) {
|
| + break;
|
| + }
|
| + last_valid_range--;
|
| + }
|
| +
|
| + if (last_valid_range < 0) {
|
| + if (!cc->is_negated()) {
|
| + macro_assembler->GoTo(on_failure);
|
| + }
|
| + if (check_offset) {
|
| + macro_assembler->CheckPosition(cp_offset, on_failure);
|
| + }
|
| + return;
|
| + }
|
| +
|
| + if (last_valid_range == 0 &&
|
| + ranges->at(0).IsEverything(max_char)) {
|
| + if (cc->is_negated()) {
|
| + macro_assembler->GoTo(on_failure);
|
| + } else {
|
| + // This is a common case hit by non-anchored expressions.
|
| + if (check_offset) {
|
| + macro_assembler->CheckPosition(cp_offset, on_failure);
|
| + }
|
| + }
|
| + return;
|
| + }
|
| + if (last_valid_range == 0 &&
|
| + !cc->is_negated() &&
|
| + ranges->at(0).IsEverything(max_char)) {
|
| + // This is a common case hit by non-anchored expressions.
|
| + if (check_offset) {
|
| + macro_assembler->CheckPosition(cp_offset, on_failure);
|
| + }
|
| + return;
|
| + }
|
| +
|
| + if (!preloaded) {
|
| + macro_assembler->LoadCurrentCharacter(cp_offset, on_failure, check_offset);
|
| + }
|
| +
|
| + if (cc->is_standard(zone) &&
|
| + macro_assembler->CheckSpecialCharacterClass(cc->standard_type(),
|
| + on_failure)) {
|
| + return;
|
| + }
|
| +
|
| +
|
| + // A new list with ascending entries. Each entry is a code unit
|
| + // where there is a boundary between code units that are part of
|
| + // the class and code units that are not. Normally we insert an
|
| + // entry at zero which goes to the failure label, but if there
|
| + // was already one there we fall through for success on that entry.
|
| + // Subsequent entries have alternating meaning (success/failure).
|
| + ZoneList<int>* range_boundaries =
|
| + new(zone) ZoneList<int>(last_valid_range, zone);
|
| +
|
| + bool zeroth_entry_is_failure = !cc->is_negated();
|
| +
|
| + for (int i = 0; i <= last_valid_range; i++) {
|
| + CharacterRange& range = ranges->at(i);
|
| + if (range.from() == 0) {
|
| + DCHECK_EQ(i, 0);
|
| + zeroth_entry_is_failure = !zeroth_entry_is_failure;
|
| + } else {
|
| + range_boundaries->Add(range.from(), zone);
|
| + }
|
| + range_boundaries->Add(range.to() + 1, zone);
|
| + }
|
| + int end_index = range_boundaries->length() - 1;
|
| + if (range_boundaries->at(end_index) > max_char) {
|
| + end_index--;
|
| + }
|
| +
|
| + Label fall_through;
|
| + GenerateBranches(macro_assembler,
|
| + range_boundaries,
|
| + 0, // start_index.
|
| + end_index,
|
| + 0, // min_char.
|
| + max_char,
|
| + &fall_through,
|
| + zeroth_entry_is_failure ? &fall_through : on_failure,
|
| + zeroth_entry_is_failure ? on_failure : &fall_through);
|
| + macro_assembler->Bind(&fall_through);
|
| +}
|
| +
|
| +
|
| +RegExpNode::~RegExpNode() {
|
| +}
|
| +
|
| +
|
| +RegExpNode::LimitResult RegExpNode::LimitVersions(RegExpCompiler* compiler,
|
| + Trace* trace) {
|
| + // If we are generating a greedy loop then don't stop and don't reuse code.
|
| + if (trace->stop_node() != NULL) {
|
| + return CONTINUE;
|
| + }
|
| +
|
| + RegExpMacroAssembler* macro_assembler = compiler->macro_assembler();
|
| + if (trace->is_trivial()) {
|
| + if (label_.is_bound()) {
|
| + // We are being asked to generate a generic version, but that's already
|
| + // been done so just go to it.
|
| + macro_assembler->GoTo(&label_);
|
| + return DONE;
|
| + }
|
| + if (compiler->recursion_depth() >= RegExpCompiler::kMaxRecursion) {
|
| + // To avoid too deep recursion we push the node to the work queue and just
|
| + // generate a goto here.
|
| + compiler->AddWork(this);
|
| + macro_assembler->GoTo(&label_);
|
| + return DONE;
|
| + }
|
| + // Generate generic version of the node and bind the label for later use.
|
| + macro_assembler->Bind(&label_);
|
| + return CONTINUE;
|
| + }
|
| +
|
| + // We are being asked to make a non-generic version. Keep track of how many
|
| + // non-generic versions we generate so as not to overdo it.
|
| + trace_count_++;
|
| + if (FLAG_regexp_optimization &&
|
| + trace_count_ < kMaxCopiesCodeGenerated &&
|
| + compiler->recursion_depth() <= RegExpCompiler::kMaxRecursion) {
|
| + return CONTINUE;
|
| + }
|
| +
|
| + // If we get here code has been generated for this node too many times or
|
| + // recursion is too deep. Time to switch to a generic version. The code for
|
| + // generic versions above can handle deep recursion properly.
|
| + trace->Flush(compiler, this);
|
| + return DONE;
|
| +}
|
| +
|
| +
|
| +int ActionNode::EatsAtLeast(int still_to_find,
|
| + int budget,
|
| + bool not_at_start) {
|
| + if (budget <= 0) return 0;
|
| + if (action_type_ == POSITIVE_SUBMATCH_SUCCESS) return 0; // Rewinds input!
|
| + return on_success()->EatsAtLeast(still_to_find,
|
| + budget - 1,
|
| + not_at_start);
|
| +}
|
| +
|
| +
|
| +void ActionNode::FillInBMInfo(int offset,
|
| + int budget,
|
| + BoyerMooreLookahead* bm,
|
| + bool not_at_start) {
|
| + if (action_type_ == BEGIN_SUBMATCH) {
|
| + bm->SetRest(offset);
|
| + } else if (action_type_ != POSITIVE_SUBMATCH_SUCCESS) {
|
| + on_success()->FillInBMInfo(offset, budget - 1, bm, not_at_start);
|
| + }
|
| + SaveBMInfo(bm, not_at_start, offset);
|
| +}
|
| +
|
| +
|
| +int AssertionNode::EatsAtLeast(int still_to_find,
|
| + int budget,
|
| + bool not_at_start) {
|
| + if (budget <= 0) return 0;
|
| + // If we know we are not at the start and we are asked "how many characters
|
| + // will you match if you succeed?" then we can answer anything since false
|
| + // implies false. So lets just return the max answer (still_to_find) since
|
| + // that won't prevent us from preloading a lot of characters for the other
|
| + // branches in the node graph.
|
| + if (assertion_type() == AT_START && not_at_start) return still_to_find;
|
| + return on_success()->EatsAtLeast(still_to_find,
|
| + budget - 1,
|
| + not_at_start);
|
| +}
|
| +
|
| +
|
| +void AssertionNode::FillInBMInfo(int offset,
|
| + int budget,
|
| + BoyerMooreLookahead* bm,
|
| + bool not_at_start) {
|
| + // Match the behaviour of EatsAtLeast on this node.
|
| + if (assertion_type() == AT_START && not_at_start) return;
|
| + on_success()->FillInBMInfo(offset, budget - 1, bm, not_at_start);
|
| + SaveBMInfo(bm, not_at_start, offset);
|
| +}
|
| +
|
| +
|
| +int BackReferenceNode::EatsAtLeast(int still_to_find,
|
| + int budget,
|
| + bool not_at_start) {
|
| + if (budget <= 0) return 0;
|
| + return on_success()->EatsAtLeast(still_to_find,
|
| + budget - 1,
|
| + not_at_start);
|
| +}
|
| +
|
| +
|
| +int TextNode::EatsAtLeast(int still_to_find,
|
| + int budget,
|
| + bool not_at_start) {
|
| + int answer = Length();
|
| + if (answer >= still_to_find) return answer;
|
| + if (budget <= 0) return answer;
|
| + // We are not at start after this node so we set the last argument to 'true'.
|
| + return answer + on_success()->EatsAtLeast(still_to_find - answer,
|
| + budget - 1,
|
| + true);
|
| +}
|
| +
|
| +
|
| +int NegativeLookaheadChoiceNode::EatsAtLeast(int still_to_find,
|
| + int budget,
|
| + bool not_at_start) {
|
| + if (budget <= 0) return 0;
|
| + // Alternative 0 is the negative lookahead, alternative 1 is what comes
|
| + // afterwards.
|
| + RegExpNode* node = alternatives_->at(1).node();
|
| + return node->EatsAtLeast(still_to_find, budget - 1, not_at_start);
|
| +}
|
| +
|
| +
|
| +void NegativeLookaheadChoiceNode::GetQuickCheckDetails(
|
| + QuickCheckDetails* details,
|
| + RegExpCompiler* compiler,
|
| + int filled_in,
|
| + bool not_at_start) {
|
| + // Alternative 0 is the negative lookahead, alternative 1 is what comes
|
| + // afterwards.
|
| + RegExpNode* node = alternatives_->at(1).node();
|
| + return node->GetQuickCheckDetails(details, compiler, filled_in, not_at_start);
|
| +}
|
| +
|
| +
|
| +int ChoiceNode::EatsAtLeastHelper(int still_to_find,
|
| + int budget,
|
| + RegExpNode* ignore_this_node,
|
| + bool not_at_start) {
|
| + if (budget <= 0) return 0;
|
| + int min = 100;
|
| + int choice_count = alternatives_->length();
|
| + budget = (budget - 1) / choice_count;
|
| + for (int i = 0; i < choice_count; i++) {
|
| + RegExpNode* node = alternatives_->at(i).node();
|
| + if (node == ignore_this_node) continue;
|
| + int node_eats_at_least =
|
| + node->EatsAtLeast(still_to_find, budget, not_at_start);
|
| + if (node_eats_at_least < min) min = node_eats_at_least;
|
| + if (min == 0) return 0;
|
| + }
|
| + return min;
|
| +}
|
| +
|
| +
|
| +int LoopChoiceNode::EatsAtLeast(int still_to_find,
|
| + int budget,
|
| + bool not_at_start) {
|
| + return EatsAtLeastHelper(still_to_find,
|
| + budget - 1,
|
| + loop_node_,
|
| + not_at_start);
|
| +}
|
| +
|
| +
|
| +int ChoiceNode::EatsAtLeast(int still_to_find,
|
| + int budget,
|
| + bool not_at_start) {
|
| + return EatsAtLeastHelper(still_to_find,
|
| + budget,
|
| + NULL,
|
| + not_at_start);
|
| +}
|
| +
|
| +
|
| +// Takes the left-most 1-bit and smears it out, setting all bits to its right.
|
| +static inline uint32_t SmearBitsRight(uint32_t v) {
|
| + v |= v >> 1;
|
| + v |= v >> 2;
|
| + v |= v >> 4;
|
| + v |= v >> 8;
|
| + v |= v >> 16;
|
| + return v;
|
| +}
|
| +
|
| +
|
| +bool QuickCheckDetails::Rationalize(bool asc) {
|
| + bool found_useful_op = false;
|
| + uint32_t char_mask;
|
| + if (asc) {
|
| + char_mask = String::kMaxOneByteCharCode;
|
| + } else {
|
| + char_mask = String::kMaxUtf16CodeUnit;
|
| + }
|
| + mask_ = 0;
|
| + value_ = 0;
|
| + int char_shift = 0;
|
| + for (int i = 0; i < characters_; i++) {
|
| + Position* pos = &positions_[i];
|
| + if ((pos->mask & String::kMaxOneByteCharCode) != 0) {
|
| + found_useful_op = true;
|
| + }
|
| + mask_ |= (pos->mask & char_mask) << char_shift;
|
| + value_ |= (pos->value & char_mask) << char_shift;
|
| + char_shift += asc ? 8 : 16;
|
| + }
|
| + return found_useful_op;
|
| +}
|
| +
|
| +
|
| +bool RegExpNode::EmitQuickCheck(RegExpCompiler* compiler,
|
| + Trace* bounds_check_trace,
|
| + Trace* trace,
|
| + bool preload_has_checked_bounds,
|
| + Label* on_possible_success,
|
| + QuickCheckDetails* details,
|
| + bool fall_through_on_failure) {
|
| + if (details->characters() == 0) return false;
|
| + GetQuickCheckDetails(
|
| + details, compiler, 0, trace->at_start() == Trace::FALSE_VALUE);
|
| + if (details->cannot_match()) return false;
|
| + if (!details->Rationalize(compiler->one_byte())) return false;
|
| + DCHECK(details->characters() == 1 ||
|
| + compiler->macro_assembler()->CanReadUnaligned());
|
| + uint32_t mask = details->mask();
|
| + uint32_t value = details->value();
|
| +
|
| + RegExpMacroAssembler* assembler = compiler->macro_assembler();
|
| +
|
| + if (trace->characters_preloaded() != details->characters()) {
|
| + DCHECK(trace->cp_offset() == bounds_check_trace->cp_offset());
|
| + // We are attempting to preload the minimum number of characters
|
| + // any choice would eat, so if the bounds check fails, then none of the
|
| + // choices can succeed, so we can just immediately backtrack, rather
|
| + // than go to the next choice.
|
| + assembler->LoadCurrentCharacter(trace->cp_offset(),
|
| + bounds_check_trace->backtrack(),
|
| + !preload_has_checked_bounds,
|
| + details->characters());
|
| + }
|
| +
|
| +
|
| + bool need_mask = true;
|
| +
|
| + if (details->characters() == 1) {
|
| + // If number of characters preloaded is 1 then we used a byte or 16 bit
|
| + // load so the value is already masked down.
|
| + uint32_t char_mask;
|
| + if (compiler->one_byte()) {
|
| + char_mask = String::kMaxOneByteCharCode;
|
| + } else {
|
| + char_mask = String::kMaxUtf16CodeUnit;
|
| + }
|
| + if ((mask & char_mask) == char_mask) need_mask = false;
|
| + mask &= char_mask;
|
| + } else {
|
| + // For 2-character preloads in one-byte mode or 1-character preloads in
|
| + // two-byte mode we also use a 16 bit load with zero extend.
|
| + if (details->characters() == 2 && compiler->one_byte()) {
|
| + if ((mask & 0xffff) == 0xffff) need_mask = false;
|
| + } else if (details->characters() == 1 && !compiler->one_byte()) {
|
| + if ((mask & 0xffff) == 0xffff) need_mask = false;
|
| + } else {
|
| + if (mask == 0xffffffff) need_mask = false;
|
| + }
|
| + }
|
| +
|
| + if (fall_through_on_failure) {
|
| + if (need_mask) {
|
| + assembler->CheckCharacterAfterAnd(value, mask, on_possible_success);
|
| + } else {
|
| + assembler->CheckCharacter(value, on_possible_success);
|
| + }
|
| + } else {
|
| + if (need_mask) {
|
| + assembler->CheckNotCharacterAfterAnd(value, mask, trace->backtrack());
|
| + } else {
|
| + assembler->CheckNotCharacter(value, trace->backtrack());
|
| + }
|
| + }
|
| + return true;
|
| +}
|
| +
|
| +
|
| +// Here is the meat of GetQuickCheckDetails (see also the comment on the
|
| +// super-class in the .h file).
|
| +//
|
| +// We iterate along the text object, building up for each character a
|
| +// mask and value that can be used to test for a quick failure to match.
|
| +// The masks and values for the positions will be combined into a single
|
| +// machine word for the current character width in order to be used in
|
| +// generating a quick check.
|
| +void TextNode::GetQuickCheckDetails(QuickCheckDetails* details,
|
| + RegExpCompiler* compiler,
|
| + int characters_filled_in,
|
| + bool not_at_start) {
|
| + Isolate* isolate = compiler->macro_assembler()->zone()->isolate();
|
| + DCHECK(characters_filled_in < details->characters());
|
| + int characters = details->characters();
|
| + int char_mask;
|
| + if (compiler->one_byte()) {
|
| + char_mask = String::kMaxOneByteCharCode;
|
| + } else {
|
| + char_mask = String::kMaxUtf16CodeUnit;
|
| + }
|
| + for (int k = 0; k < elms_->length(); k++) {
|
| + TextElement elm = elms_->at(k);
|
| + if (elm.text_type() == TextElement::ATOM) {
|
| + Vector<const uc16> quarks = elm.atom()->data();
|
| + for (int i = 0; i < characters && i < quarks.length(); i++) {
|
| + QuickCheckDetails::Position* pos =
|
| + details->positions(characters_filled_in);
|
| + uc16 c = quarks[i];
|
| + if (c > char_mask) {
|
| + // If we expect a non-Latin1 character from an one-byte string,
|
| + // there is no way we can match. Not even case-independent
|
| + // matching can turn an Latin1 character into non-Latin1 or
|
| + // vice versa.
|
| + // TODO(dcarney): issue 3550. Verify that this works as expected.
|
| + // For example, \u0178 is uppercase of \u00ff (y-umlaut).
|
| + details->set_cannot_match();
|
| + pos->determines_perfectly = false;
|
| + return;
|
| + }
|
| + if (compiler->ignore_case()) {
|
| + unibrow::uchar chars[unibrow::Ecma262UnCanonicalize::kMaxWidth];
|
| + int length = GetCaseIndependentLetters(isolate, c,
|
| + compiler->one_byte(), chars);
|
| + DCHECK(length != 0); // Can only happen if c > char_mask (see above).
|
| + if (length == 1) {
|
| + // This letter has no case equivalents, so it's nice and simple
|
| + // and the mask-compare will determine definitely whether we have
|
| + // a match at this character position.
|
| + pos->mask = char_mask;
|
| + pos->value = c;
|
| + pos->determines_perfectly = true;
|
| + } else {
|
| + uint32_t common_bits = char_mask;
|
| + uint32_t bits = chars[0];
|
| + for (int j = 1; j < length; j++) {
|
| + uint32_t differing_bits = ((chars[j] & common_bits) ^ bits);
|
| + common_bits ^= differing_bits;
|
| + bits &= common_bits;
|
| + }
|
| + // If length is 2 and common bits has only one zero in it then
|
| + // our mask and compare instruction will determine definitely
|
| + // whether we have a match at this character position. Otherwise
|
| + // it can only be an approximate check.
|
| + uint32_t one_zero = (common_bits | ~char_mask);
|
| + if (length == 2 && ((~one_zero) & ((~one_zero) - 1)) == 0) {
|
| + pos->determines_perfectly = true;
|
| + }
|
| + pos->mask = common_bits;
|
| + pos->value = bits;
|
| + }
|
| + } else {
|
| + // Don't ignore case. Nice simple case where the mask-compare will
|
| + // determine definitely whether we have a match at this character
|
| + // position.
|
| + pos->mask = char_mask;
|
| + pos->value = c;
|
| + pos->determines_perfectly = true;
|
| + }
|
| + characters_filled_in++;
|
| + DCHECK(characters_filled_in <= details->characters());
|
| + if (characters_filled_in == details->characters()) {
|
| + return;
|
| + }
|
| + }
|
| + } else {
|
| + QuickCheckDetails::Position* pos =
|
| + details->positions(characters_filled_in);
|
| + RegExpCharacterClass* tree = elm.char_class();
|
| + ZoneList<CharacterRange>* ranges = tree->ranges(zone());
|
| + if (tree->is_negated()) {
|
| + // A quick check uses multi-character mask and compare. There is no
|
| + // useful way to incorporate a negative char class into this scheme
|
| + // so we just conservatively create a mask and value that will always
|
| + // succeed.
|
| + pos->mask = 0;
|
| + pos->value = 0;
|
| + } else {
|
| + int first_range = 0;
|
| + while (ranges->at(first_range).from() > char_mask) {
|
| + first_range++;
|
| + if (first_range == ranges->length()) {
|
| + details->set_cannot_match();
|
| + pos->determines_perfectly = false;
|
| + return;
|
| + }
|
| + }
|
| + CharacterRange range = ranges->at(first_range);
|
| + uc16 from = range.from();
|
| + uc16 to = range.to();
|
| + if (to > char_mask) {
|
| + to = char_mask;
|
| + }
|
| + uint32_t differing_bits = (from ^ to);
|
| + // A mask and compare is only perfect if the differing bits form a
|
| + // number like 00011111 with one single block of trailing 1s.
|
| + if ((differing_bits & (differing_bits + 1)) == 0 &&
|
| + from + differing_bits == to) {
|
| + pos->determines_perfectly = true;
|
| + }
|
| + uint32_t common_bits = ~SmearBitsRight(differing_bits);
|
| + uint32_t bits = (from & common_bits);
|
| + for (int i = first_range + 1; i < ranges->length(); i++) {
|
| + CharacterRange range = ranges->at(i);
|
| + uc16 from = range.from();
|
| + uc16 to = range.to();
|
| + if (from > char_mask) continue;
|
| + if (to > char_mask) to = char_mask;
|
| + // Here we are combining more ranges into the mask and compare
|
| + // value. With each new range the mask becomes more sparse and
|
| + // so the chances of a false positive rise. A character class
|
| + // with multiple ranges is assumed never to be equivalent to a
|
| + // mask and compare operation.
|
| + pos->determines_perfectly = false;
|
| + uint32_t new_common_bits = (from ^ to);
|
| + new_common_bits = ~SmearBitsRight(new_common_bits);
|
| + common_bits &= new_common_bits;
|
| + bits &= new_common_bits;
|
| + uint32_t differing_bits = (from & common_bits) ^ bits;
|
| + common_bits ^= differing_bits;
|
| + bits &= common_bits;
|
| + }
|
| + pos->mask = common_bits;
|
| + pos->value = bits;
|
| + }
|
| + characters_filled_in++;
|
| + DCHECK(characters_filled_in <= details->characters());
|
| + if (characters_filled_in == details->characters()) {
|
| + return;
|
| + }
|
| + }
|
| + }
|
| + DCHECK(characters_filled_in != details->characters());
|
| + if (!details->cannot_match()) {
|
| + on_success()-> GetQuickCheckDetails(details,
|
| + compiler,
|
| + characters_filled_in,
|
| + true);
|
| + }
|
| +}
|
| +
|
| +
|
| +void QuickCheckDetails::Clear() {
|
| + for (int i = 0; i < characters_; i++) {
|
| + positions_[i].mask = 0;
|
| + positions_[i].value = 0;
|
| + positions_[i].determines_perfectly = false;
|
| + }
|
| + characters_ = 0;
|
| +}
|
| +
|
| +
|
| +void QuickCheckDetails::Advance(int by, bool one_byte) {
|
| + DCHECK(by >= 0);
|
| + if (by >= characters_) {
|
| + Clear();
|
| + return;
|
| + }
|
| + for (int i = 0; i < characters_ - by; i++) {
|
| + positions_[i] = positions_[by + i];
|
| + }
|
| + for (int i = characters_ - by; i < characters_; i++) {
|
| + positions_[i].mask = 0;
|
| + positions_[i].value = 0;
|
| + positions_[i].determines_perfectly = false;
|
| + }
|
| + characters_ -= by;
|
| + // We could change mask_ and value_ here but we would never advance unless
|
| + // they had already been used in a check and they won't be used again because
|
| + // it would gain us nothing. So there's no point.
|
| +}
|
| +
|
| +
|
| +void QuickCheckDetails::Merge(QuickCheckDetails* other, int from_index) {
|
| + DCHECK(characters_ == other->characters_);
|
| + if (other->cannot_match_) {
|
| + return;
|
| + }
|
| + if (cannot_match_) {
|
| + *this = *other;
|
| + return;
|
| + }
|
| + for (int i = from_index; i < characters_; i++) {
|
| + QuickCheckDetails::Position* pos = positions(i);
|
| + QuickCheckDetails::Position* other_pos = other->positions(i);
|
| + if (pos->mask != other_pos->mask ||
|
| + pos->value != other_pos->value ||
|
| + !other_pos->determines_perfectly) {
|
| + // Our mask-compare operation will be approximate unless we have the
|
| + // exact same operation on both sides of the alternation.
|
| + pos->determines_perfectly = false;
|
| + }
|
| + pos->mask &= other_pos->mask;
|
| + pos->value &= pos->mask;
|
| + other_pos->value &= pos->mask;
|
| + uc16 differing_bits = (pos->value ^ other_pos->value);
|
| + pos->mask &= ~differing_bits;
|
| + pos->value &= pos->mask;
|
| + }
|
| +}
|
| +
|
| +
|
| +class VisitMarker {
|
| + public:
|
| + explicit VisitMarker(NodeInfo* info) : info_(info) {
|
| + DCHECK(!info->visited);
|
| + info->visited = true;
|
| + }
|
| + ~VisitMarker() {
|
| + info_->visited = false;
|
| + }
|
| + private:
|
| + NodeInfo* info_;
|
| +};
|
| +
|
| +
|
| +RegExpNode* SeqRegExpNode::FilterOneByte(int depth, bool ignore_case) {
|
| + if (info()->replacement_calculated) return replacement();
|
| + if (depth < 0) return this;
|
| + DCHECK(!info()->visited);
|
| + VisitMarker marker(info());
|
| + return FilterSuccessor(depth - 1, ignore_case);
|
| +}
|
| +
|
| +
|
| +RegExpNode* SeqRegExpNode::FilterSuccessor(int depth, bool ignore_case) {
|
| + RegExpNode* next = on_success_->FilterOneByte(depth - 1, ignore_case);
|
| + if (next == NULL) return set_replacement(NULL);
|
| + on_success_ = next;
|
| + return set_replacement(this);
|
| +}
|
| +
|
| +
|
| +// We need to check for the following characters: 0x39c 0x3bc 0x178.
|
| +static inline bool RangeContainsLatin1Equivalents(CharacterRange range) {
|
| + // TODO(dcarney): this could be a lot more efficient.
|
| + return range.Contains(0x39c) ||
|
| + range.Contains(0x3bc) || range.Contains(0x178);
|
| +}
|
| +
|
| +
|
| +static bool RangesContainLatin1Equivalents(ZoneList<CharacterRange>* ranges) {
|
| + for (int i = 0; i < ranges->length(); i++) {
|
| + // TODO(dcarney): this could be a lot more efficient.
|
| + if (RangeContainsLatin1Equivalents(ranges->at(i))) return true;
|
| + }
|
| + return false;
|
| +}
|
| +
|
| +
|
| +RegExpNode* TextNode::FilterOneByte(int depth, bool ignore_case) {
|
| + if (info()->replacement_calculated) return replacement();
|
| + if (depth < 0) return this;
|
| + DCHECK(!info()->visited);
|
| + VisitMarker marker(info());
|
| + int element_count = elms_->length();
|
| + for (int i = 0; i < element_count; i++) {
|
| + TextElement elm = elms_->at(i);
|
| + if (elm.text_type() == TextElement::ATOM) {
|
| + Vector<const uc16> quarks = elm.atom()->data();
|
| + for (int j = 0; j < quarks.length(); j++) {
|
| + uint16_t c = quarks[j];
|
| + if (c <= String::kMaxOneByteCharCode) continue;
|
| + if (!ignore_case) return set_replacement(NULL);
|
| + // Here, we need to check for characters whose upper and lower cases
|
| + // are outside the Latin-1 range.
|
| + uint16_t converted = unibrow::Latin1::ConvertNonLatin1ToLatin1(c);
|
| + // Character is outside Latin-1 completely
|
| + if (converted == 0) return set_replacement(NULL);
|
| + // Convert quark to Latin-1 in place.
|
| + uint16_t* copy = const_cast<uint16_t*>(quarks.start());
|
| + copy[j] = converted;
|
| + }
|
| + } else {
|
| + DCHECK(elm.text_type() == TextElement::CHAR_CLASS);
|
| + RegExpCharacterClass* cc = elm.char_class();
|
| + ZoneList<CharacterRange>* ranges = cc->ranges(zone());
|
| + if (!CharacterRange::IsCanonical(ranges)) {
|
| + CharacterRange::Canonicalize(ranges);
|
| + }
|
| + // Now they are in order so we only need to look at the first.
|
| + int range_count = ranges->length();
|
| + if (cc->is_negated()) {
|
| + if (range_count != 0 &&
|
| + ranges->at(0).from() == 0 &&
|
| + ranges->at(0).to() >= String::kMaxOneByteCharCode) {
|
| + // This will be handled in a later filter.
|
| + if (ignore_case && RangesContainLatin1Equivalents(ranges)) continue;
|
| + return set_replacement(NULL);
|
| + }
|
| + } else {
|
| + if (range_count == 0 ||
|
| + ranges->at(0).from() > String::kMaxOneByteCharCode) {
|
| + // This will be handled in a later filter.
|
| + if (ignore_case && RangesContainLatin1Equivalents(ranges)) continue;
|
| + return set_replacement(NULL);
|
| + }
|
| + }
|
| + }
|
| + }
|
| + return FilterSuccessor(depth - 1, ignore_case);
|
| +}
|
| +
|
| +
|
| +RegExpNode* LoopChoiceNode::FilterOneByte(int depth, bool ignore_case) {
|
| + if (info()->replacement_calculated) return replacement();
|
| + if (depth < 0) return this;
|
| + if (info()->visited) return this;
|
| + {
|
| + VisitMarker marker(info());
|
| +
|
| + RegExpNode* continue_replacement =
|
| + continue_node_->FilterOneByte(depth - 1, ignore_case);
|
| + // If we can't continue after the loop then there is no sense in doing the
|
| + // loop.
|
| + if (continue_replacement == NULL) return set_replacement(NULL);
|
| + }
|
| +
|
| + return ChoiceNode::FilterOneByte(depth - 1, ignore_case);
|
| +}
|
| +
|
| +
|
| +RegExpNode* ChoiceNode::FilterOneByte(int depth, bool ignore_case) {
|
| + if (info()->replacement_calculated) return replacement();
|
| + if (depth < 0) return this;
|
| + if (info()->visited) return this;
|
| + VisitMarker marker(info());
|
| + int choice_count = alternatives_->length();
|
| +
|
| + for (int i = 0; i < choice_count; i++) {
|
| + GuardedAlternative alternative = alternatives_->at(i);
|
| + if (alternative.guards() != NULL && alternative.guards()->length() != 0) {
|
| + set_replacement(this);
|
| + return this;
|
| + }
|
| + }
|
| +
|
| + int surviving = 0;
|
| + RegExpNode* survivor = NULL;
|
| + for (int i = 0; i < choice_count; i++) {
|
| + GuardedAlternative alternative = alternatives_->at(i);
|
| + RegExpNode* replacement =
|
| + alternative.node()->FilterOneByte(depth - 1, ignore_case);
|
| + DCHECK(replacement != this); // No missing EMPTY_MATCH_CHECK.
|
| + if (replacement != NULL) {
|
| + alternatives_->at(i).set_node(replacement);
|
| + surviving++;
|
| + survivor = replacement;
|
| + }
|
| + }
|
| + if (surviving < 2) return set_replacement(survivor);
|
| +
|
| + set_replacement(this);
|
| + if (surviving == choice_count) {
|
| + return this;
|
| + }
|
| + // Only some of the nodes survived the filtering. We need to rebuild the
|
| + // alternatives list.
|
| + ZoneList<GuardedAlternative>* new_alternatives =
|
| + new(zone()) ZoneList<GuardedAlternative>(surviving, zone());
|
| + for (int i = 0; i < choice_count; i++) {
|
| + RegExpNode* replacement =
|
| + alternatives_->at(i).node()->FilterOneByte(depth - 1, ignore_case);
|
| + if (replacement != NULL) {
|
| + alternatives_->at(i).set_node(replacement);
|
| + new_alternatives->Add(alternatives_->at(i), zone());
|
| + }
|
| + }
|
| + alternatives_ = new_alternatives;
|
| + return this;
|
| +}
|
| +
|
| +
|
| +RegExpNode* NegativeLookaheadChoiceNode::FilterOneByte(int depth,
|
| + bool ignore_case) {
|
| + if (info()->replacement_calculated) return replacement();
|
| + if (depth < 0) return this;
|
| + if (info()->visited) return this;
|
| + VisitMarker marker(info());
|
| + // Alternative 0 is the negative lookahead, alternative 1 is what comes
|
| + // afterwards.
|
| + RegExpNode* node = alternatives_->at(1).node();
|
| + RegExpNode* replacement = node->FilterOneByte(depth - 1, ignore_case);
|
| + if (replacement == NULL) return set_replacement(NULL);
|
| + alternatives_->at(1).set_node(replacement);
|
| +
|
| + RegExpNode* neg_node = alternatives_->at(0).node();
|
| + RegExpNode* neg_replacement = neg_node->FilterOneByte(depth - 1, ignore_case);
|
| + // If the negative lookahead is always going to fail then
|
| + // we don't need to check it.
|
| + if (neg_replacement == NULL) return set_replacement(replacement);
|
| + alternatives_->at(0).set_node(neg_replacement);
|
| + return set_replacement(this);
|
| +}
|
| +
|
| +
|
| +void LoopChoiceNode::GetQuickCheckDetails(QuickCheckDetails* details,
|
| + RegExpCompiler* compiler,
|
| + int characters_filled_in,
|
| + bool not_at_start) {
|
| + if (body_can_be_zero_length_ || info()->visited) return;
|
| + VisitMarker marker(info());
|
| + return ChoiceNode::GetQuickCheckDetails(details,
|
| + compiler,
|
| + characters_filled_in,
|
| + not_at_start);
|
| +}
|
| +
|
| +
|
| +void LoopChoiceNode::FillInBMInfo(int offset,
|
| + int budget,
|
| + BoyerMooreLookahead* bm,
|
| + bool not_at_start) {
|
| + if (body_can_be_zero_length_ || budget <= 0) {
|
| + bm->SetRest(offset);
|
| + SaveBMInfo(bm, not_at_start, offset);
|
| + return;
|
| + }
|
| + ChoiceNode::FillInBMInfo(offset, budget - 1, bm, not_at_start);
|
| + SaveBMInfo(bm, not_at_start, offset);
|
| +}
|
| +
|
| +
|
| +void ChoiceNode::GetQuickCheckDetails(QuickCheckDetails* details,
|
| + RegExpCompiler* compiler,
|
| + int characters_filled_in,
|
| + bool not_at_start) {
|
| + not_at_start = (not_at_start || not_at_start_);
|
| + int choice_count = alternatives_->length();
|
| + DCHECK(choice_count > 0);
|
| + alternatives_->at(0).node()->GetQuickCheckDetails(details,
|
| + compiler,
|
| + characters_filled_in,
|
| + not_at_start);
|
| + for (int i = 1; i < choice_count; i++) {
|
| + QuickCheckDetails new_details(details->characters());
|
| + RegExpNode* node = alternatives_->at(i).node();
|
| + node->GetQuickCheckDetails(&new_details, compiler,
|
| + characters_filled_in,
|
| + not_at_start);
|
| + // Here we merge the quick match details of the two branches.
|
| + details->Merge(&new_details, characters_filled_in);
|
| + }
|
| +}
|
| +
|
| +
|
| +// Check for [0-9A-Z_a-z].
|
| +static void EmitWordCheck(RegExpMacroAssembler* assembler,
|
| + Label* word,
|
| + Label* non_word,
|
| + bool fall_through_on_word) {
|
| + if (assembler->CheckSpecialCharacterClass(
|
| + fall_through_on_word ? 'w' : 'W',
|
| + fall_through_on_word ? non_word : word)) {
|
| + // Optimized implementation available.
|
| + return;
|
| + }
|
| + assembler->CheckCharacterGT('z', non_word);
|
| + assembler->CheckCharacterLT('0', non_word);
|
| + assembler->CheckCharacterGT('a' - 1, word);
|
| + assembler->CheckCharacterLT('9' + 1, word);
|
| + assembler->CheckCharacterLT('A', non_word);
|
| + assembler->CheckCharacterLT('Z' + 1, word);
|
| + if (fall_through_on_word) {
|
| + assembler->CheckNotCharacter('_', non_word);
|
| + } else {
|
| + assembler->CheckCharacter('_', word);
|
| + }
|
| +}
|
| +
|
| +
|
| +// Emit the code to check for a ^ in multiline mode (1-character lookbehind
|
| +// that matches newline or the start of input).
|
| +static void EmitHat(RegExpCompiler* compiler,
|
| + RegExpNode* on_success,
|
| + Trace* trace) {
|
| + RegExpMacroAssembler* assembler = compiler->macro_assembler();
|
| + // We will be loading the previous character into the current character
|
| + // register.
|
| + Trace new_trace(*trace);
|
| + new_trace.InvalidateCurrentCharacter();
|
| +
|
| + Label ok;
|
| + if (new_trace.cp_offset() == 0) {
|
| + // The start of input counts as a newline in this context, so skip to
|
| + // ok if we are at the start.
|
| + assembler->CheckAtStart(&ok);
|
| + }
|
| + // We already checked that we are not at the start of input so it must be
|
| + // OK to load the previous character.
|
| + assembler->LoadCurrentCharacter(new_trace.cp_offset() -1,
|
| + new_trace.backtrack(),
|
| + false);
|
| + if (!assembler->CheckSpecialCharacterClass('n',
|
| + new_trace.backtrack())) {
|
| + // Newline means \n, \r, 0x2028 or 0x2029.
|
| + if (!compiler->one_byte()) {
|
| + assembler->CheckCharacterAfterAnd(0x2028, 0xfffe, &ok);
|
| + }
|
| + assembler->CheckCharacter('\n', &ok);
|
| + assembler->CheckNotCharacter('\r', new_trace.backtrack());
|
| + }
|
| + assembler->Bind(&ok);
|
| + on_success->Emit(compiler, &new_trace);
|
| +}
|
| +
|
| +
|
| +// Emit the code to handle \b and \B (word-boundary or non-word-boundary).
|
| +void AssertionNode::EmitBoundaryCheck(RegExpCompiler* compiler, Trace* trace) {
|
| + RegExpMacroAssembler* assembler = compiler->macro_assembler();
|
| + Trace::TriBool next_is_word_character = Trace::UNKNOWN;
|
| + bool not_at_start = (trace->at_start() == Trace::FALSE_VALUE);
|
| + BoyerMooreLookahead* lookahead = bm_info(not_at_start);
|
| + if (lookahead == NULL) {
|
| + int eats_at_least =
|
| + Min(kMaxLookaheadForBoyerMoore, EatsAtLeast(kMaxLookaheadForBoyerMoore,
|
| + kRecursionBudget,
|
| + not_at_start));
|
| + if (eats_at_least >= 1) {
|
| + BoyerMooreLookahead* bm =
|
| + new(zone()) BoyerMooreLookahead(eats_at_least, compiler, zone());
|
| + FillInBMInfo(0, kRecursionBudget, bm, not_at_start);
|
| + if (bm->at(0)->is_non_word())
|
| + next_is_word_character = Trace::FALSE_VALUE;
|
| + if (bm->at(0)->is_word()) next_is_word_character = Trace::TRUE_VALUE;
|
| + }
|
| + } else {
|
| + if (lookahead->at(0)->is_non_word())
|
| + next_is_word_character = Trace::FALSE_VALUE;
|
| + if (lookahead->at(0)->is_word())
|
| + next_is_word_character = Trace::TRUE_VALUE;
|
| + }
|
| + bool at_boundary = (assertion_type_ == AssertionNode::AT_BOUNDARY);
|
| + if (next_is_word_character == Trace::UNKNOWN) {
|
| + Label before_non_word;
|
| + Label before_word;
|
| + if (trace->characters_preloaded() != 1) {
|
| + assembler->LoadCurrentCharacter(trace->cp_offset(), &before_non_word);
|
| + }
|
| + // Fall through on non-word.
|
| + EmitWordCheck(assembler, &before_word, &before_non_word, false);
|
| + // Next character is not a word character.
|
| + assembler->Bind(&before_non_word);
|
| + Label ok;
|
| + BacktrackIfPrevious(compiler, trace, at_boundary ? kIsNonWord : kIsWord);
|
| + assembler->GoTo(&ok);
|
| +
|
| + assembler->Bind(&before_word);
|
| + BacktrackIfPrevious(compiler, trace, at_boundary ? kIsWord : kIsNonWord);
|
| + assembler->Bind(&ok);
|
| + } else if (next_is_word_character == Trace::TRUE_VALUE) {
|
| + BacktrackIfPrevious(compiler, trace, at_boundary ? kIsWord : kIsNonWord);
|
| + } else {
|
| + DCHECK(next_is_word_character == Trace::FALSE_VALUE);
|
| + BacktrackIfPrevious(compiler, trace, at_boundary ? kIsNonWord : kIsWord);
|
| + }
|
| +}
|
| +
|
| +
|
| +void AssertionNode::BacktrackIfPrevious(
|
| + RegExpCompiler* compiler,
|
| + Trace* trace,
|
| + AssertionNode::IfPrevious backtrack_if_previous) {
|
| + RegExpMacroAssembler* assembler = compiler->macro_assembler();
|
| + Trace new_trace(*trace);
|
| + new_trace.InvalidateCurrentCharacter();
|
| +
|
| + Label fall_through, dummy;
|
| +
|
| + Label* non_word = backtrack_if_previous == kIsNonWord ?
|
| + new_trace.backtrack() :
|
| + &fall_through;
|
| + Label* word = backtrack_if_previous == kIsNonWord ?
|
| + &fall_through :
|
| + new_trace.backtrack();
|
| +
|
| + if (new_trace.cp_offset() == 0) {
|
| + // The start of input counts as a non-word character, so the question is
|
| + // decided if we are at the start.
|
| + assembler->CheckAtStart(non_word);
|
| + }
|
| + // We already checked that we are not at the start of input so it must be
|
| + // OK to load the previous character.
|
| + assembler->LoadCurrentCharacter(new_trace.cp_offset() - 1, &dummy, false);
|
| + EmitWordCheck(assembler, word, non_word, backtrack_if_previous == kIsNonWord);
|
| +
|
| + assembler->Bind(&fall_through);
|
| + on_success()->Emit(compiler, &new_trace);
|
| +}
|
| +
|
| +
|
| +void AssertionNode::GetQuickCheckDetails(QuickCheckDetails* details,
|
| + RegExpCompiler* compiler,
|
| + int filled_in,
|
| + bool not_at_start) {
|
| + if (assertion_type_ == AT_START && not_at_start) {
|
| + details->set_cannot_match();
|
| + return;
|
| + }
|
| + return on_success()->GetQuickCheckDetails(details,
|
| + compiler,
|
| + filled_in,
|
| + not_at_start);
|
| +}
|
| +
|
| +
|
| +void AssertionNode::Emit(RegExpCompiler* compiler, Trace* trace) {
|
| + RegExpMacroAssembler* assembler = compiler->macro_assembler();
|
| + switch (assertion_type_) {
|
| + case AT_END: {
|
| + Label ok;
|
| + assembler->CheckPosition(trace->cp_offset(), &ok);
|
| + assembler->GoTo(trace->backtrack());
|
| + assembler->Bind(&ok);
|
| + break;
|
| + }
|
| + case AT_START: {
|
| + if (trace->at_start() == Trace::FALSE_VALUE) {
|
| + assembler->GoTo(trace->backtrack());
|
| + return;
|
| + }
|
| + if (trace->at_start() == Trace::UNKNOWN) {
|
| + assembler->CheckNotAtStart(trace->backtrack());
|
| + Trace at_start_trace = *trace;
|
| + at_start_trace.set_at_start(true);
|
| + on_success()->Emit(compiler, &at_start_trace);
|
| + return;
|
| + }
|
| + }
|
| + break;
|
| + case AFTER_NEWLINE:
|
| + EmitHat(compiler, on_success(), trace);
|
| + return;
|
| + case AT_BOUNDARY:
|
| + case AT_NON_BOUNDARY: {
|
| + EmitBoundaryCheck(compiler, trace);
|
| + return;
|
| + }
|
| + }
|
| + on_success()->Emit(compiler, trace);
|
| +}
|
| +
|
| +
|
| +static bool DeterminedAlready(QuickCheckDetails* quick_check, int offset) {
|
| + if (quick_check == NULL) return false;
|
| + if (offset >= quick_check->characters()) return false;
|
| + return quick_check->positions(offset)->determines_perfectly;
|
| +}
|
| +
|
| +
|
| +static void UpdateBoundsCheck(int index, int* checked_up_to) {
|
| + if (index > *checked_up_to) {
|
| + *checked_up_to = index;
|
| + }
|
| +}
|
| +
|
| +
|
| +// We call this repeatedly to generate code for each pass over the text node.
|
| +// The passes are in increasing order of difficulty because we hope one
|
| +// of the first passes will fail in which case we are saved the work of the
|
| +// later passes. for example for the case independent regexp /%[asdfghjkl]a/
|
| +// we will check the '%' in the first pass, the case independent 'a' in the
|
| +// second pass and the character class in the last pass.
|
| +//
|
| +// The passes are done from right to left, so for example to test for /bar/
|
| +// we will first test for an 'r' with offset 2, then an 'a' with offset 1
|
| +// and then a 'b' with offset 0. This means we can avoid the end-of-input
|
| +// bounds check most of the time. In the example we only need to check for
|
| +// end-of-input when loading the putative 'r'.
|
| +//
|
| +// A slight complication involves the fact that the first character may already
|
| +// be fetched into a register by the previous node. In this case we want to
|
| +// do the test for that character first. We do this in separate passes. The
|
| +// 'preloaded' argument indicates that we are doing such a 'pass'. If such a
|
| +// pass has been performed then subsequent passes will have true in
|
| +// first_element_checked to indicate that that character does not need to be
|
| +// checked again.
|
| +//
|
| +// In addition to all this we are passed a Trace, which can
|
| +// contain an AlternativeGeneration object. In this AlternativeGeneration
|
| +// object we can see details of any quick check that was already passed in
|
| +// order to get to the code we are now generating. The quick check can involve
|
| +// loading characters, which means we do not need to recheck the bounds
|
| +// up to the limit the quick check already checked. In addition the quick
|
| +// check can have involved a mask and compare operation which may simplify
|
| +// or obviate the need for further checks at some character positions.
|
| +void TextNode::TextEmitPass(RegExpCompiler* compiler,
|
| + TextEmitPassType pass,
|
| + bool preloaded,
|
| + Trace* trace,
|
| + bool first_element_checked,
|
| + int* checked_up_to) {
|
| + RegExpMacroAssembler* assembler = compiler->macro_assembler();
|
| + Isolate* isolate = assembler->zone()->isolate();
|
| + bool one_byte = compiler->one_byte();
|
| + Label* backtrack = trace->backtrack();
|
| + QuickCheckDetails* quick_check = trace->quick_check_performed();
|
| + int element_count = elms_->length();
|
| + for (int i = preloaded ? 0 : element_count - 1; i >= 0; i--) {
|
| + TextElement elm = elms_->at(i);
|
| + int cp_offset = trace->cp_offset() + elm.cp_offset();
|
| + if (elm.text_type() == TextElement::ATOM) {
|
| + Vector<const uc16> quarks = elm.atom()->data();
|
| + for (int j = preloaded ? 0 : quarks.length() - 1; j >= 0; j--) {
|
| + if (first_element_checked && i == 0 && j == 0) continue;
|
| + if (DeterminedAlready(quick_check, elm.cp_offset() + j)) continue;
|
| + EmitCharacterFunction* emit_function = NULL;
|
| + switch (pass) {
|
| + case NON_LATIN1_MATCH:
|
| + DCHECK(one_byte);
|
| + if (quarks[j] > String::kMaxOneByteCharCode) {
|
| + assembler->GoTo(backtrack);
|
| + return;
|
| + }
|
| + break;
|
| + case NON_LETTER_CHARACTER_MATCH:
|
| + emit_function = &EmitAtomNonLetter;
|
| + break;
|
| + case SIMPLE_CHARACTER_MATCH:
|
| + emit_function = &EmitSimpleCharacter;
|
| + break;
|
| + case CASE_CHARACTER_MATCH:
|
| + emit_function = &EmitAtomLetter;
|
| + break;
|
| + default:
|
| + break;
|
| + }
|
| + if (emit_function != NULL) {
|
| + bool bound_checked = emit_function(isolate,
|
| + compiler,
|
| + quarks[j],
|
| + backtrack,
|
| + cp_offset + j,
|
| + *checked_up_to < cp_offset + j,
|
| + preloaded);
|
| + if (bound_checked) UpdateBoundsCheck(cp_offset + j, checked_up_to);
|
| + }
|
| + }
|
| + } else {
|
| + DCHECK_EQ(TextElement::CHAR_CLASS, elm.text_type());
|
| + if (pass == CHARACTER_CLASS_MATCH) {
|
| + if (first_element_checked && i == 0) continue;
|
| + if (DeterminedAlready(quick_check, elm.cp_offset())) continue;
|
| + RegExpCharacterClass* cc = elm.char_class();
|
| + EmitCharClass(assembler, cc, one_byte, backtrack, cp_offset,
|
| + *checked_up_to < cp_offset, preloaded, zone());
|
| + UpdateBoundsCheck(cp_offset, checked_up_to);
|
| + }
|
| + }
|
| + }
|
| +}
|
| +
|
| +
|
| +int TextNode::Length() {
|
| + TextElement elm = elms_->last();
|
| + DCHECK(elm.cp_offset() >= 0);
|
| + return elm.cp_offset() + elm.length();
|
| +}
|
| +
|
| +
|
| +bool TextNode::SkipPass(int int_pass, bool ignore_case) {
|
| + TextEmitPassType pass = static_cast<TextEmitPassType>(int_pass);
|
| + if (ignore_case) {
|
| + return pass == SIMPLE_CHARACTER_MATCH;
|
| + } else {
|
| + return pass == NON_LETTER_CHARACTER_MATCH || pass == CASE_CHARACTER_MATCH;
|
| + }
|
| +}
|
| +
|
| +
|
| +// This generates the code to match a text node. A text node can contain
|
| +// straight character sequences (possibly to be matched in a case-independent
|
| +// way) and character classes. For efficiency we do not do this in a single
|
| +// pass from left to right. Instead we pass over the text node several times,
|
| +// emitting code for some character positions every time. See the comment on
|
| +// TextEmitPass for details.
|
| +void TextNode::Emit(RegExpCompiler* compiler, Trace* trace) {
|
| + LimitResult limit_result = LimitVersions(compiler, trace);
|
| + if (limit_result == DONE) return;
|
| + DCHECK(limit_result == CONTINUE);
|
| +
|
| + if (trace->cp_offset() + Length() > RegExpMacroAssembler::kMaxCPOffset) {
|
| + compiler->SetRegExpTooBig();
|
| + return;
|
| + }
|
| +
|
| + if (compiler->one_byte()) {
|
| + int dummy = 0;
|
| + TextEmitPass(compiler, NON_LATIN1_MATCH, false, trace, false, &dummy);
|
| + }
|
| +
|
| + bool first_elt_done = false;
|
| + int bound_checked_to = trace->cp_offset() - 1;
|
| + bound_checked_to += trace->bound_checked_up_to();
|
| +
|
| + // If a character is preloaded into the current character register then
|
| + // check that now.
|
| + if (trace->characters_preloaded() == 1) {
|
| + for (int pass = kFirstRealPass; pass <= kLastPass; pass++) {
|
| + if (!SkipPass(pass, compiler->ignore_case())) {
|
| + TextEmitPass(compiler,
|
| + static_cast<TextEmitPassType>(pass),
|
| + true,
|
| + trace,
|
| + false,
|
| + &bound_checked_to);
|
| + }
|
| + }
|
| + first_elt_done = true;
|
| + }
|
| +
|
| + for (int pass = kFirstRealPass; pass <= kLastPass; pass++) {
|
| + if (!SkipPass(pass, compiler->ignore_case())) {
|
| + TextEmitPass(compiler,
|
| + static_cast<TextEmitPassType>(pass),
|
| + false,
|
| + trace,
|
| + first_elt_done,
|
| + &bound_checked_to);
|
| + }
|
| + }
|
| +
|
| + Trace successor_trace(*trace);
|
| + successor_trace.set_at_start(false);
|
| + successor_trace.AdvanceCurrentPositionInTrace(Length(), compiler);
|
| + RecursionCheck rc(compiler);
|
| + on_success()->Emit(compiler, &successor_trace);
|
| +}
|
| +
|
| +
|
| +void Trace::InvalidateCurrentCharacter() {
|
| + characters_preloaded_ = 0;
|
| +}
|
| +
|
| +
|
| +void Trace::AdvanceCurrentPositionInTrace(int by, RegExpCompiler* compiler) {
|
| + DCHECK(by > 0);
|
| + // We don't have an instruction for shifting the current character register
|
| + // down or for using a shifted value for anything so lets just forget that
|
| + // we preloaded any characters into it.
|
| + characters_preloaded_ = 0;
|
| + // Adjust the offsets of the quick check performed information. This
|
| + // information is used to find out what we already determined about the
|
| + // characters by means of mask and compare.
|
| + quick_check_performed_.Advance(by, compiler->one_byte());
|
| + cp_offset_ += by;
|
| + if (cp_offset_ > RegExpMacroAssembler::kMaxCPOffset) {
|
| + compiler->SetRegExpTooBig();
|
| + cp_offset_ = 0;
|
| + }
|
| + bound_checked_up_to_ = Max(0, bound_checked_up_to_ - by);
|
| +}
|
| +
|
| +
|
| +void TextNode::MakeCaseIndependent(bool is_one_byte) {
|
| + int element_count = elms_->length();
|
| + for (int i = 0; i < element_count; i++) {
|
| + TextElement elm = elms_->at(i);
|
| + if (elm.text_type() == TextElement::CHAR_CLASS) {
|
| + RegExpCharacterClass* cc = elm.char_class();
|
| + // None of the standard character classes is different in the case
|
| + // independent case and it slows us down if we don't know that.
|
| + if (cc->is_standard(zone())) continue;
|
| + ZoneList<CharacterRange>* ranges = cc->ranges(zone());
|
| + int range_count = ranges->length();
|
| + for (int j = 0; j < range_count; j++) {
|
| + ranges->at(j).AddCaseEquivalents(ranges, is_one_byte, zone());
|
| + }
|
| + }
|
| + }
|
| +}
|
| +
|
| +
|
| +int TextNode::GreedyLoopTextLength() {
|
| + TextElement elm = elms_->at(elms_->length() - 1);
|
| + return elm.cp_offset() + elm.length();
|
| +}
|
| +
|
| +
|
| +RegExpNode* TextNode::GetSuccessorOfOmnivorousTextNode(
|
| + RegExpCompiler* compiler) {
|
| + if (elms_->length() != 1) return NULL;
|
| + TextElement elm = elms_->at(0);
|
| + if (elm.text_type() != TextElement::CHAR_CLASS) return NULL;
|
| + RegExpCharacterClass* node = elm.char_class();
|
| + ZoneList<CharacterRange>* ranges = node->ranges(zone());
|
| + if (!CharacterRange::IsCanonical(ranges)) {
|
| + CharacterRange::Canonicalize(ranges);
|
| + }
|
| + if (node->is_negated()) {
|
| + return ranges->length() == 0 ? on_success() : NULL;
|
| + }
|
| + if (ranges->length() != 1) return NULL;
|
| + uint32_t max_char;
|
| + if (compiler->one_byte()) {
|
| + max_char = String::kMaxOneByteCharCode;
|
| + } else {
|
| + max_char = String::kMaxUtf16CodeUnit;
|
| + }
|
| + return ranges->at(0).IsEverything(max_char) ? on_success() : NULL;
|
| +}
|
| +
|
| +
|
| +// Finds the fixed match length of a sequence of nodes that goes from
|
| +// this alternative and back to this choice node. If there are variable
|
| +// length nodes or other complications in the way then return a sentinel
|
| +// value indicating that a greedy loop cannot be constructed.
|
| +int ChoiceNode::GreedyLoopTextLengthForAlternative(
|
| + GuardedAlternative* alternative) {
|
| + int length = 0;
|
| + RegExpNode* node = alternative->node();
|
| + // Later we will generate code for all these text nodes using recursion
|
| + // so we have to limit the max number.
|
| + int recursion_depth = 0;
|
| + while (node != this) {
|
| + if (recursion_depth++ > RegExpCompiler::kMaxRecursion) {
|
| + return kNodeIsTooComplexForGreedyLoops;
|
| + }
|
| + int node_length = node->GreedyLoopTextLength();
|
| + if (node_length == kNodeIsTooComplexForGreedyLoops) {
|
| + return kNodeIsTooComplexForGreedyLoops;
|
| + }
|
| + length += node_length;
|
| + SeqRegExpNode* seq_node = static_cast<SeqRegExpNode*>(node);
|
| + node = seq_node->on_success();
|
| + }
|
| + return length;
|
| +}
|
| +
|
| +
|
| +void LoopChoiceNode::AddLoopAlternative(GuardedAlternative alt) {
|
| + DCHECK_EQ(loop_node_, NULL);
|
| + AddAlternative(alt);
|
| + loop_node_ = alt.node();
|
| +}
|
| +
|
| +
|
| +void LoopChoiceNode::AddContinueAlternative(GuardedAlternative alt) {
|
| + DCHECK_EQ(continue_node_, NULL);
|
| + AddAlternative(alt);
|
| + continue_node_ = alt.node();
|
| +}
|
| +
|
| +
|
| +void LoopChoiceNode::Emit(RegExpCompiler* compiler, Trace* trace) {
|
| + RegExpMacroAssembler* macro_assembler = compiler->macro_assembler();
|
| + if (trace->stop_node() == this) {
|
| + // Back edge of greedy optimized loop node graph.
|
| + int text_length =
|
| + GreedyLoopTextLengthForAlternative(&(alternatives_->at(0)));
|
| + DCHECK(text_length != kNodeIsTooComplexForGreedyLoops);
|
| + // Update the counter-based backtracking info on the stack. This is an
|
| + // optimization for greedy loops (see below).
|
| + DCHECK(trace->cp_offset() == text_length);
|
| + macro_assembler->AdvanceCurrentPosition(text_length);
|
| + macro_assembler->GoTo(trace->loop_label());
|
| + return;
|
| + }
|
| + DCHECK(trace->stop_node() == NULL);
|
| + if (!trace->is_trivial()) {
|
| + trace->Flush(compiler, this);
|
| + return;
|
| + }
|
| + ChoiceNode::Emit(compiler, trace);
|
| +}
|
| +
|
| +
|
| +int ChoiceNode::CalculatePreloadCharacters(RegExpCompiler* compiler,
|
| + int eats_at_least) {
|
| + int preload_characters = Min(4, eats_at_least);
|
| + if (compiler->macro_assembler()->CanReadUnaligned()) {
|
| + bool one_byte = compiler->one_byte();
|
| + if (one_byte) {
|
| + if (preload_characters > 4) preload_characters = 4;
|
| + // We can't preload 3 characters because there is no machine instruction
|
| + // to do that. We can't just load 4 because we could be reading
|
| + // beyond the end of the string, which could cause a memory fault.
|
| + if (preload_characters == 3) preload_characters = 2;
|
| + } else {
|
| + if (preload_characters > 2) preload_characters = 2;
|
| + }
|
| + } else {
|
| + if (preload_characters > 1) preload_characters = 1;
|
| + }
|
| + return preload_characters;
|
| +}
|
| +
|
| +
|
| +// This class is used when generating the alternatives in a choice node. It
|
| +// records the way the alternative is being code generated.
|
| +class AlternativeGeneration: public Malloced {
|
| + public:
|
| + AlternativeGeneration()
|
| + : possible_success(),
|
| + expects_preload(false),
|
| + after(),
|
| + quick_check_details() { }
|
| + Label possible_success;
|
| + bool expects_preload;
|
| + Label after;
|
| + QuickCheckDetails quick_check_details;
|
| +};
|
| +
|
| +
|
| +// Creates a list of AlternativeGenerations. If the list has a reasonable
|
| +// size then it is on the stack, otherwise the excess is on the heap.
|
| +class AlternativeGenerationList {
|
| + public:
|
| + AlternativeGenerationList(int count, Zone* zone)
|
| + : alt_gens_(count, zone) {
|
| + for (int i = 0; i < count && i < kAFew; i++) {
|
| + alt_gens_.Add(a_few_alt_gens_ + i, zone);
|
| + }
|
| + for (int i = kAFew; i < count; i++) {
|
| + alt_gens_.Add(new AlternativeGeneration(), zone);
|
| + }
|
| + }
|
| + ~AlternativeGenerationList() {
|
| + for (int i = kAFew; i < alt_gens_.length(); i++) {
|
| + delete alt_gens_[i];
|
| + alt_gens_[i] = NULL;
|
| + }
|
| + }
|
| +
|
| + AlternativeGeneration* at(int i) {
|
| + return alt_gens_[i];
|
| + }
|
| +
|
| + private:
|
| + static const int kAFew = 10;
|
| + ZoneList<AlternativeGeneration*> alt_gens_;
|
| + AlternativeGeneration a_few_alt_gens_[kAFew];
|
| +};
|
| +
|
| +
|
| +// The '2' variant is has inclusive from and exclusive to.
|
| +// This covers \s as defined in ECMA-262 5.1, 15.10.2.12,
|
| +// which include WhiteSpace (7.2) or LineTerminator (7.3) values.
|
| +static const int kSpaceRanges[] = { '\t', '\r' + 1, ' ', ' ' + 1,
|
| + 0x00A0, 0x00A1, 0x1680, 0x1681, 0x180E, 0x180F, 0x2000, 0x200B,
|
| + 0x2028, 0x202A, 0x202F, 0x2030, 0x205F, 0x2060, 0x3000, 0x3001,
|
| + 0xFEFF, 0xFF00, 0x10000 };
|
| +static const int kSpaceRangeCount = arraysize(kSpaceRanges);
|
| +
|
| +static const int kWordRanges[] = {
|
| + '0', '9' + 1, 'A', 'Z' + 1, '_', '_' + 1, 'a', 'z' + 1, 0x10000 };
|
| +static const int kWordRangeCount = arraysize(kWordRanges);
|
| +static const int kDigitRanges[] = { '0', '9' + 1, 0x10000 };
|
| +static const int kDigitRangeCount = arraysize(kDigitRanges);
|
| +static const int kSurrogateRanges[] = { 0xd800, 0xe000, 0x10000 };
|
| +static const int kSurrogateRangeCount = arraysize(kSurrogateRanges);
|
| +static const int kLineTerminatorRanges[] = { 0x000A, 0x000B, 0x000D, 0x000E,
|
| + 0x2028, 0x202A, 0x10000 };
|
| +static const int kLineTerminatorRangeCount = arraysize(kLineTerminatorRanges);
|
| +
|
| +
|
| +void BoyerMoorePositionInfo::Set(int character) {
|
| + SetInterval(Interval(character, character));
|
| +}
|
| +
|
| +
|
| +void BoyerMoorePositionInfo::SetInterval(const Interval& interval) {
|
| + s_ = AddRange(s_, kSpaceRanges, kSpaceRangeCount, interval);
|
| + w_ = AddRange(w_, kWordRanges, kWordRangeCount, interval);
|
| + d_ = AddRange(d_, kDigitRanges, kDigitRangeCount, interval);
|
| + surrogate_ =
|
| + AddRange(surrogate_, kSurrogateRanges, kSurrogateRangeCount, interval);
|
| + if (interval.to() - interval.from() >= kMapSize - 1) {
|
| + if (map_count_ != kMapSize) {
|
| + map_count_ = kMapSize;
|
| + for (int i = 0; i < kMapSize; i++) map_->at(i) = true;
|
| + }
|
| + return;
|
| + }
|
| + for (int i = interval.from(); i <= interval.to(); i++) {
|
| + int mod_character = (i & kMask);
|
| + if (!map_->at(mod_character)) {
|
| + map_count_++;
|
| + map_->at(mod_character) = true;
|
| + }
|
| + if (map_count_ == kMapSize) return;
|
| + }
|
| +}
|
| +
|
| +
|
| +void BoyerMoorePositionInfo::SetAll() {
|
| + s_ = w_ = d_ = kLatticeUnknown;
|
| + if (map_count_ != kMapSize) {
|
| + map_count_ = kMapSize;
|
| + for (int i = 0; i < kMapSize; i++) map_->at(i) = true;
|
| + }
|
| +}
|
| +
|
| +
|
| +BoyerMooreLookahead::BoyerMooreLookahead(
|
| + int length, RegExpCompiler* compiler, Zone* zone)
|
| + : length_(length),
|
| + compiler_(compiler) {
|
| + if (compiler->one_byte()) {
|
| + max_char_ = String::kMaxOneByteCharCode;
|
| + } else {
|
| + max_char_ = String::kMaxUtf16CodeUnit;
|
| + }
|
| + bitmaps_ = new(zone) ZoneList<BoyerMoorePositionInfo*>(length, zone);
|
| + for (int i = 0; i < length; i++) {
|
| + bitmaps_->Add(new(zone) BoyerMoorePositionInfo(zone), zone);
|
| + }
|
| +}
|
| +
|
| +
|
| +// Find the longest range of lookahead that has the fewest number of different
|
| +// characters that can occur at a given position. Since we are optimizing two
|
| +// different parameters at once this is a tradeoff.
|
| +bool BoyerMooreLookahead::FindWorthwhileInterval(int* from, int* to) {
|
| + int biggest_points = 0;
|
| + // If more than 32 characters out of 128 can occur it is unlikely that we can
|
| + // be lucky enough to step forwards much of the time.
|
| + const int kMaxMax = 32;
|
| + for (int max_number_of_chars = 4;
|
| + max_number_of_chars < kMaxMax;
|
| + max_number_of_chars *= 2) {
|
| + biggest_points =
|
| + FindBestInterval(max_number_of_chars, biggest_points, from, to);
|
| + }
|
| + if (biggest_points == 0) return false;
|
| + return true;
|
| +}
|
| +
|
| +
|
| +// Find the highest-points range between 0 and length_ where the character
|
| +// information is not too vague. 'Too vague' means that there are more than
|
| +// max_number_of_chars that can occur at this position. Calculates the number
|
| +// of points as the product of width-of-the-range and
|
| +// probability-of-finding-one-of-the-characters, where the probability is
|
| +// calculated using the frequency distribution of the sample subject string.
|
| +int BoyerMooreLookahead::FindBestInterval(
|
| + int max_number_of_chars, int old_biggest_points, int* from, int* to) {
|
| + int biggest_points = old_biggest_points;
|
| + static const int kSize = RegExpMacroAssembler::kTableSize;
|
| + for (int i = 0; i < length_; ) {
|
| + while (i < length_ && Count(i) > max_number_of_chars) i++;
|
| + if (i == length_) break;
|
| + int remembered_from = i;
|
| + bool union_map[kSize];
|
| + for (int j = 0; j < kSize; j++) union_map[j] = false;
|
| + while (i < length_ && Count(i) <= max_number_of_chars) {
|
| + BoyerMoorePositionInfo* map = bitmaps_->at(i);
|
| + for (int j = 0; j < kSize; j++) union_map[j] |= map->at(j);
|
| + i++;
|
| + }
|
| + int frequency = 0;
|
| + for (int j = 0; j < kSize; j++) {
|
| + if (union_map[j]) {
|
| + // Add 1 to the frequency to give a small per-character boost for
|
| + // the cases where our sampling is not good enough and many
|
| + // characters have a frequency of zero. This means the frequency
|
| + // can theoretically be up to 2*kSize though we treat it mostly as
|
| + // a fraction of kSize.
|
| + frequency += compiler_->frequency_collator()->Frequency(j) + 1;
|
| + }
|
| + }
|
| + // We use the probability of skipping times the distance we are skipping to
|
| + // judge the effectiveness of this. Actually we have a cut-off: By
|
| + // dividing by 2 we switch off the skipping if the probability of skipping
|
| + // is less than 50%. This is because the multibyte mask-and-compare
|
| + // skipping in quickcheck is more likely to do well on this case.
|
| + bool in_quickcheck_range =
|
| + ((i - remembered_from < 4) ||
|
| + (compiler_->one_byte() ? remembered_from <= 4 : remembered_from <= 2));
|
| + // Called 'probability' but it is only a rough estimate and can actually
|
| + // be outside the 0-kSize range.
|
| + int probability = (in_quickcheck_range ? kSize / 2 : kSize) - frequency;
|
| + int points = (i - remembered_from) * probability;
|
| + if (points > biggest_points) {
|
| + *from = remembered_from;
|
| + *to = i - 1;
|
| + biggest_points = points;
|
| + }
|
| + }
|
| + return biggest_points;
|
| +}
|
| +
|
| +
|
| +// Take all the characters that will not prevent a successful match if they
|
| +// occur in the subject string in the range between min_lookahead and
|
| +// max_lookahead (inclusive) measured from the current position. If the
|
| +// character at max_lookahead offset is not one of these characters, then we
|
| +// can safely skip forwards by the number of characters in the range.
|
| +int BoyerMooreLookahead::GetSkipTable(int min_lookahead,
|
| + int max_lookahead,
|
| + Handle<ByteArray> boolean_skip_table) {
|
| + const int kSize = RegExpMacroAssembler::kTableSize;
|
| +
|
| + const int kSkipArrayEntry = 0;
|
| + const int kDontSkipArrayEntry = 1;
|
| +
|
| + for (int i = 0; i < kSize; i++) {
|
| + boolean_skip_table->set(i, kSkipArrayEntry);
|
| + }
|
| + int skip = max_lookahead + 1 - min_lookahead;
|
| +
|
| + for (int i = max_lookahead; i >= min_lookahead; i--) {
|
| + BoyerMoorePositionInfo* map = bitmaps_->at(i);
|
| + for (int j = 0; j < kSize; j++) {
|
| + if (map->at(j)) {
|
| + boolean_skip_table->set(j, kDontSkipArrayEntry);
|
| + }
|
| + }
|
| + }
|
| +
|
| + return skip;
|
| +}
|
| +
|
| +
|
| +// See comment above on the implementation of GetSkipTable.
|
| +void BoyerMooreLookahead::EmitSkipInstructions(RegExpMacroAssembler* masm) {
|
| + const int kSize = RegExpMacroAssembler::kTableSize;
|
| +
|
| + int min_lookahead = 0;
|
| + int max_lookahead = 0;
|
| +
|
| + if (!FindWorthwhileInterval(&min_lookahead, &max_lookahead)) return;
|
| +
|
| + bool found_single_character = false;
|
| + int single_character = 0;
|
| + for (int i = max_lookahead; i >= min_lookahead; i--) {
|
| + BoyerMoorePositionInfo* map = bitmaps_->at(i);
|
| + if (map->map_count() > 1 ||
|
| + (found_single_character && map->map_count() != 0)) {
|
| + found_single_character = false;
|
| + break;
|
| + }
|
| + for (int j = 0; j < kSize; j++) {
|
| + if (map->at(j)) {
|
| + found_single_character = true;
|
| + single_character = j;
|
| + break;
|
| + }
|
| + }
|
| + }
|
| +
|
| + int lookahead_width = max_lookahead + 1 - min_lookahead;
|
| +
|
| + if (found_single_character && lookahead_width == 1 && max_lookahead < 3) {
|
| + // The mask-compare can probably handle this better.
|
| + return;
|
| + }
|
| +
|
| + if (found_single_character) {
|
| + Label cont, again;
|
| + masm->Bind(&again);
|
| + masm->LoadCurrentCharacter(max_lookahead, &cont, true);
|
| + if (max_char_ > kSize) {
|
| + masm->CheckCharacterAfterAnd(single_character,
|
| + RegExpMacroAssembler::kTableMask,
|
| + &cont);
|
| + } else {
|
| + masm->CheckCharacter(single_character, &cont);
|
| + }
|
| + masm->AdvanceCurrentPosition(lookahead_width);
|
| + masm->GoTo(&again);
|
| + masm->Bind(&cont);
|
| + return;
|
| + }
|
| +
|
| + Factory* factory = masm->zone()->isolate()->factory();
|
| + Handle<ByteArray> boolean_skip_table = factory->NewByteArray(kSize, TENURED);
|
| + int skip_distance = GetSkipTable(
|
| + min_lookahead, max_lookahead, boolean_skip_table);
|
| + DCHECK(skip_distance != 0);
|
| +
|
| + Label cont, again;
|
| + masm->Bind(&again);
|
| + masm->LoadCurrentCharacter(max_lookahead, &cont, true);
|
| + masm->CheckBitInTable(boolean_skip_table, &cont);
|
| + masm->AdvanceCurrentPosition(skip_distance);
|
| + masm->GoTo(&again);
|
| + masm->Bind(&cont);
|
| +}
|
| +
|
| +
|
| +/* Code generation for choice nodes.
|
| + *
|
| + * We generate quick checks that do a mask and compare to eliminate a
|
| + * choice. If the quick check succeeds then it jumps to the continuation to
|
| + * do slow checks and check subsequent nodes. If it fails (the common case)
|
| + * it falls through to the next choice.
|
| + *
|
| + * Here is the desired flow graph. Nodes directly below each other imply
|
| + * fallthrough. Alternatives 1 and 2 have quick checks. Alternative
|
| + * 3 doesn't have a quick check so we have to call the slow check.
|
| + * Nodes are marked Qn for quick checks and Sn for slow checks. The entire
|
| + * regexp continuation is generated directly after the Sn node, up to the
|
| + * next GoTo if we decide to reuse some already generated code. Some
|
| + * nodes expect preload_characters to be preloaded into the current
|
| + * character register. R nodes do this preloading. Vertices are marked
|
| + * F for failures and S for success (possible success in the case of quick
|
| + * nodes). L, V, < and > are used as arrow heads.
|
| + *
|
| + * ----------> R
|
| + * |
|
| + * V
|
| + * Q1 -----> S1
|
| + * | S /
|
| + * F| /
|
| + * | F/
|
| + * | /
|
| + * | R
|
| + * | /
|
| + * V L
|
| + * Q2 -----> S2
|
| + * | S /
|
| + * F| /
|
| + * | F/
|
| + * | /
|
| + * | R
|
| + * | /
|
| + * V L
|
| + * S3
|
| + * |
|
| + * F|
|
| + * |
|
| + * R
|
| + * |
|
| + * backtrack V
|
| + * <----------Q4
|
| + * \ F |
|
| + * \ |S
|
| + * \ F V
|
| + * \-----S4
|
| + *
|
| + * For greedy loops we push the current position, then generate the code that
|
| + * eats the input specially in EmitGreedyLoop. The other choice (the
|
| + * continuation) is generated by the normal code in EmitChoices, and steps back
|
| + * in the input to the starting position when it fails to match. The loop code
|
| + * looks like this (U is the unwind code that steps back in the greedy loop).
|
| + *
|
| + * _____
|
| + * / \
|
| + * V |
|
| + * ----------> S1 |
|
| + * /| |
|
| + * / |S |
|
| + * F/ \_____/
|
| + * /
|
| + * |<-----
|
| + * | \
|
| + * V |S
|
| + * Q2 ---> U----->backtrack
|
| + * | F /
|
| + * S| /
|
| + * V F /
|
| + * S2--/
|
| + */
|
| +
|
| +GreedyLoopState::GreedyLoopState(bool not_at_start) {
|
| + counter_backtrack_trace_.set_backtrack(&label_);
|
| + if (not_at_start) counter_backtrack_trace_.set_at_start(false);
|
| +}
|
| +
|
| +
|
| +void ChoiceNode::AssertGuardsMentionRegisters(Trace* trace) {
|
| +#ifdef DEBUG
|
| + int choice_count = alternatives_->length();
|
| + for (int i = 0; i < choice_count - 1; i++) {
|
| + GuardedAlternative alternative = alternatives_->at(i);
|
| + ZoneList<Guard*>* guards = alternative.guards();
|
| + int guard_count = (guards == NULL) ? 0 : guards->length();
|
| + for (int j = 0; j < guard_count; j++) {
|
| + DCHECK(!trace->mentions_reg(guards->at(j)->reg()));
|
| + }
|
| + }
|
| +#endif
|
| +}
|
| +
|
| +
|
| +void ChoiceNode::SetUpPreLoad(RegExpCompiler* compiler,
|
| + Trace* current_trace,
|
| + PreloadState* state) {
|
| + if (state->eats_at_least_ == PreloadState::kEatsAtLeastNotYetInitialized) {
|
| + // Save some time by looking at most one machine word ahead.
|
| + state->eats_at_least_ =
|
| + EatsAtLeast(compiler->one_byte() ? 4 : 2, kRecursionBudget,
|
| + current_trace->at_start() == Trace::FALSE_VALUE);
|
| + }
|
| + state->preload_characters_ =
|
| + CalculatePreloadCharacters(compiler, state->eats_at_least_);
|
| +
|
| + state->preload_is_current_ =
|
| + (current_trace->characters_preloaded() == state->preload_characters_);
|
| + state->preload_has_checked_bounds_ = state->preload_is_current_;
|
| +}
|
| +
|
| +
|
| +void ChoiceNode::Emit(RegExpCompiler* compiler, Trace* trace) {
|
| + int choice_count = alternatives_->length();
|
| +
|
| + AssertGuardsMentionRegisters(trace);
|
| +
|
| + LimitResult limit_result = LimitVersions(compiler, trace);
|
| + if (limit_result == DONE) return;
|
| + DCHECK(limit_result == CONTINUE);
|
| +
|
| + // For loop nodes we already flushed (see LoopChoiceNode::Emit), but for
|
| + // other choice nodes we only flush if we are out of code size budget.
|
| + if (trace->flush_budget() == 0 && trace->actions() != NULL) {
|
| + trace->Flush(compiler, this);
|
| + return;
|
| + }
|
| +
|
| + RecursionCheck rc(compiler);
|
| +
|
| + PreloadState preload;
|
| + preload.init();
|
| + GreedyLoopState greedy_loop_state(not_at_start());
|
| +
|
| + int text_length = GreedyLoopTextLengthForAlternative(&alternatives_->at(0));
|
| + AlternativeGenerationList alt_gens(choice_count, zone());
|
| +
|
| + if (choice_count > 1 && text_length != kNodeIsTooComplexForGreedyLoops) {
|
| + trace = EmitGreedyLoop(compiler,
|
| + trace,
|
| + &alt_gens,
|
| + &preload,
|
| + &greedy_loop_state,
|
| + text_length);
|
| + } else {
|
| + // TODO(erikcorry): Delete this. We don't need this label, but it makes us
|
| + // match the traces produced pre-cleanup.
|
| + Label second_choice;
|
| + compiler->macro_assembler()->Bind(&second_choice);
|
| +
|
| + preload.eats_at_least_ = EmitOptimizedUnanchoredSearch(compiler, trace);
|
| +
|
| + EmitChoices(compiler,
|
| + &alt_gens,
|
| + 0,
|
| + trace,
|
| + &preload);
|
| + }
|
| +
|
| + // At this point we need to generate slow checks for the alternatives where
|
| + // the quick check was inlined. We can recognize these because the associated
|
| + // label was bound.
|
| + int new_flush_budget = trace->flush_budget() / choice_count;
|
| + for (int i = 0; i < choice_count; i++) {
|
| + AlternativeGeneration* alt_gen = alt_gens.at(i);
|
| + Trace new_trace(*trace);
|
| + // If there are actions to be flushed we have to limit how many times
|
| + // they are flushed. Take the budget of the parent trace and distribute
|
| + // it fairly amongst the children.
|
| + if (new_trace.actions() != NULL) {
|
| + new_trace.set_flush_budget(new_flush_budget);
|
| + }
|
| + bool next_expects_preload =
|
| + i == choice_count - 1 ? false : alt_gens.at(i + 1)->expects_preload;
|
| + EmitOutOfLineContinuation(compiler,
|
| + &new_trace,
|
| + alternatives_->at(i),
|
| + alt_gen,
|
| + preload.preload_characters_,
|
| + next_expects_preload);
|
| + }
|
| +}
|
| +
|
| +
|
| +Trace* ChoiceNode::EmitGreedyLoop(RegExpCompiler* compiler,
|
| + Trace* trace,
|
| + AlternativeGenerationList* alt_gens,
|
| + PreloadState* preload,
|
| + GreedyLoopState* greedy_loop_state,
|
| + int text_length) {
|
| + RegExpMacroAssembler* macro_assembler = compiler->macro_assembler();
|
| + // Here we have special handling for greedy loops containing only text nodes
|
| + // and other simple nodes. These are handled by pushing the current
|
| + // position on the stack and then incrementing the current position each
|
| + // time around the switch. On backtrack we decrement the current position
|
| + // and check it against the pushed value. This avoids pushing backtrack
|
| + // information for each iteration of the loop, which could take up a lot of
|
| + // space.
|
| + DCHECK(trace->stop_node() == NULL);
|
| + macro_assembler->PushCurrentPosition();
|
| + Label greedy_match_failed;
|
| + Trace greedy_match_trace;
|
| + if (not_at_start()) greedy_match_trace.set_at_start(false);
|
| + greedy_match_trace.set_backtrack(&greedy_match_failed);
|
| + Label loop_label;
|
| + macro_assembler->Bind(&loop_label);
|
| + greedy_match_trace.set_stop_node(this);
|
| + greedy_match_trace.set_loop_label(&loop_label);
|
| + alternatives_->at(0).node()->Emit(compiler, &greedy_match_trace);
|
| + macro_assembler->Bind(&greedy_match_failed);
|
| +
|
| + Label second_choice; // For use in greedy matches.
|
| + macro_assembler->Bind(&second_choice);
|
| +
|
| + Trace* new_trace = greedy_loop_state->counter_backtrack_trace();
|
| +
|
| + EmitChoices(compiler,
|
| + alt_gens,
|
| + 1,
|
| + new_trace,
|
| + preload);
|
| +
|
| + macro_assembler->Bind(greedy_loop_state->label());
|
| + // If we have unwound to the bottom then backtrack.
|
| + macro_assembler->CheckGreedyLoop(trace->backtrack());
|
| + // Otherwise try the second priority at an earlier position.
|
| + macro_assembler->AdvanceCurrentPosition(-text_length);
|
| + macro_assembler->GoTo(&second_choice);
|
| + return new_trace;
|
| +}
|
| +
|
| +int ChoiceNode::EmitOptimizedUnanchoredSearch(RegExpCompiler* compiler,
|
| + Trace* trace) {
|
| + int eats_at_least = PreloadState::kEatsAtLeastNotYetInitialized;
|
| + if (alternatives_->length() != 2) return eats_at_least;
|
| +
|
| + GuardedAlternative alt1 = alternatives_->at(1);
|
| + if (alt1.guards() != NULL && alt1.guards()->length() != 0) {
|
| + return eats_at_least;
|
| + }
|
| + RegExpNode* eats_anything_node = alt1.node();
|
| + if (eats_anything_node->GetSuccessorOfOmnivorousTextNode(compiler) != this) {
|
| + return eats_at_least;
|
| + }
|
| +
|
| + // Really we should be creating a new trace when we execute this function,
|
| + // but there is no need, because the code it generates cannot backtrack, and
|
| + // we always arrive here with a trivial trace (since it's the entry to a
|
| + // loop. That also implies that there are no preloaded characters, which is
|
| + // good, because it means we won't be violating any assumptions by
|
| + // overwriting those characters with new load instructions.
|
| + DCHECK(trace->is_trivial());
|
| +
|
| + RegExpMacroAssembler* macro_assembler = compiler->macro_assembler();
|
| + // At this point we know that we are at a non-greedy loop that will eat
|
| + // any character one at a time. Any non-anchored regexp has such a
|
| + // loop prepended to it in order to find where it starts. We look for
|
| + // a pattern of the form ...abc... where we can look 6 characters ahead
|
| + // and step forwards 3 if the character is not one of abc. Abc need
|
| + // not be atoms, they can be any reasonably limited character class or
|
| + // small alternation.
|
| + BoyerMooreLookahead* bm = bm_info(false);
|
| + if (bm == NULL) {
|
| + eats_at_least = Min(kMaxLookaheadForBoyerMoore,
|
| + EatsAtLeast(kMaxLookaheadForBoyerMoore,
|
| + kRecursionBudget,
|
| + false));
|
| + if (eats_at_least >= 1) {
|
| + bm = new(zone()) BoyerMooreLookahead(eats_at_least,
|
| + compiler,
|
| + zone());
|
| + GuardedAlternative alt0 = alternatives_->at(0);
|
| + alt0.node()->FillInBMInfo(0, kRecursionBudget, bm, false);
|
| + }
|
| + }
|
| + if (bm != NULL) {
|
| + bm->EmitSkipInstructions(macro_assembler);
|
| + }
|
| + return eats_at_least;
|
| +}
|
| +
|
| +
|
| +void ChoiceNode::EmitChoices(RegExpCompiler* compiler,
|
| + AlternativeGenerationList* alt_gens,
|
| + int first_choice,
|
| + Trace* trace,
|
| + PreloadState* preload) {
|
| + RegExpMacroAssembler* macro_assembler = compiler->macro_assembler();
|
| + SetUpPreLoad(compiler, trace, preload);
|
| +
|
| + // For now we just call all choices one after the other. The idea ultimately
|
| + // is to use the Dispatch table to try only the relevant ones.
|
| + int choice_count = alternatives_->length();
|
| +
|
| + int new_flush_budget = trace->flush_budget() / choice_count;
|
| +
|
| + for (int i = first_choice; i < choice_count; i++) {
|
| + bool is_last = i == choice_count - 1;
|
| + bool fall_through_on_failure = !is_last;
|
| + GuardedAlternative alternative = alternatives_->at(i);
|
| + AlternativeGeneration* alt_gen = alt_gens->at(i);
|
| + alt_gen->quick_check_details.set_characters(preload->preload_characters_);
|
| + ZoneList<Guard*>* guards = alternative.guards();
|
| + int guard_count = (guards == NULL) ? 0 : guards->length();
|
| + Trace new_trace(*trace);
|
| + new_trace.set_characters_preloaded(preload->preload_is_current_ ?
|
| + preload->preload_characters_ :
|
| + 0);
|
| + if (preload->preload_has_checked_bounds_) {
|
| + new_trace.set_bound_checked_up_to(preload->preload_characters_);
|
| + }
|
| + new_trace.quick_check_performed()->Clear();
|
| + if (not_at_start_) new_trace.set_at_start(Trace::FALSE_VALUE);
|
| + if (!is_last) {
|
| + new_trace.set_backtrack(&alt_gen->after);
|
| + }
|
| + alt_gen->expects_preload = preload->preload_is_current_;
|
| + bool generate_full_check_inline = false;
|
| + if (FLAG_regexp_optimization &&
|
| + try_to_emit_quick_check_for_alternative(i == 0) &&
|
| + alternative.node()->EmitQuickCheck(compiler,
|
| + trace,
|
| + &new_trace,
|
| + preload->preload_has_checked_bounds_,
|
| + &alt_gen->possible_success,
|
| + &alt_gen->quick_check_details,
|
| + fall_through_on_failure)) {
|
| + // Quick check was generated for this choice.
|
| + preload->preload_is_current_ = true;
|
| + preload->preload_has_checked_bounds_ = true;
|
| + // If we generated the quick check to fall through on possible success,
|
| + // we now need to generate the full check inline.
|
| + if (!fall_through_on_failure) {
|
| + macro_assembler->Bind(&alt_gen->possible_success);
|
| + new_trace.set_quick_check_performed(&alt_gen->quick_check_details);
|
| + new_trace.set_characters_preloaded(preload->preload_characters_);
|
| + new_trace.set_bound_checked_up_to(preload->preload_characters_);
|
| + generate_full_check_inline = true;
|
| + }
|
| + } else if (alt_gen->quick_check_details.cannot_match()) {
|
| + if (!fall_through_on_failure) {
|
| + macro_assembler->GoTo(trace->backtrack());
|
| + }
|
| + continue;
|
| + } else {
|
| + // No quick check was generated. Put the full code here.
|
| + // If this is not the first choice then there could be slow checks from
|
| + // previous cases that go here when they fail. There's no reason to
|
| + // insist that they preload characters since the slow check we are about
|
| + // to generate probably can't use it.
|
| + if (i != first_choice) {
|
| + alt_gen->expects_preload = false;
|
| + new_trace.InvalidateCurrentCharacter();
|
| + }
|
| + generate_full_check_inline = true;
|
| + }
|
| + if (generate_full_check_inline) {
|
| + if (new_trace.actions() != NULL) {
|
| + new_trace.set_flush_budget(new_flush_budget);
|
| + }
|
| + for (int j = 0; j < guard_count; j++) {
|
| + GenerateGuard(macro_assembler, guards->at(j), &new_trace);
|
| + }
|
| + alternative.node()->Emit(compiler, &new_trace);
|
| + preload->preload_is_current_ = false;
|
| + }
|
| + macro_assembler->Bind(&alt_gen->after);
|
| + }
|
| +}
|
| +
|
| +
|
| +void ChoiceNode::EmitOutOfLineContinuation(RegExpCompiler* compiler,
|
| + Trace* trace,
|
| + GuardedAlternative alternative,
|
| + AlternativeGeneration* alt_gen,
|
| + int preload_characters,
|
| + bool next_expects_preload) {
|
| + if (!alt_gen->possible_success.is_linked()) return;
|
| +
|
| + RegExpMacroAssembler* macro_assembler = compiler->macro_assembler();
|
| + macro_assembler->Bind(&alt_gen->possible_success);
|
| + Trace out_of_line_trace(*trace);
|
| + out_of_line_trace.set_characters_preloaded(preload_characters);
|
| + out_of_line_trace.set_quick_check_performed(&alt_gen->quick_check_details);
|
| + if (not_at_start_) out_of_line_trace.set_at_start(Trace::FALSE_VALUE);
|
| + ZoneList<Guard*>* guards = alternative.guards();
|
| + int guard_count = (guards == NULL) ? 0 : guards->length();
|
| + if (next_expects_preload) {
|
| + Label reload_current_char;
|
| + out_of_line_trace.set_backtrack(&reload_current_char);
|
| + for (int j = 0; j < guard_count; j++) {
|
| + GenerateGuard(macro_assembler, guards->at(j), &out_of_line_trace);
|
| + }
|
| + alternative.node()->Emit(compiler, &out_of_line_trace);
|
| + macro_assembler->Bind(&reload_current_char);
|
| + // Reload the current character, since the next quick check expects that.
|
| + // We don't need to check bounds here because we only get into this
|
| + // code through a quick check which already did the checked load.
|
| + macro_assembler->LoadCurrentCharacter(trace->cp_offset(),
|
| + NULL,
|
| + false,
|
| + preload_characters);
|
| + macro_assembler->GoTo(&(alt_gen->after));
|
| + } else {
|
| + out_of_line_trace.set_backtrack(&(alt_gen->after));
|
| + for (int j = 0; j < guard_count; j++) {
|
| + GenerateGuard(macro_assembler, guards->at(j), &out_of_line_trace);
|
| + }
|
| + alternative.node()->Emit(compiler, &out_of_line_trace);
|
| + }
|
| +}
|
| +
|
| +
|
| +void ActionNode::Emit(RegExpCompiler* compiler, Trace* trace) {
|
| + RegExpMacroAssembler* assembler = compiler->macro_assembler();
|
| + LimitResult limit_result = LimitVersions(compiler, trace);
|
| + if (limit_result == DONE) return;
|
| + DCHECK(limit_result == CONTINUE);
|
| +
|
| + RecursionCheck rc(compiler);
|
| +
|
| + switch (action_type_) {
|
| + case STORE_POSITION: {
|
| + Trace::DeferredCapture
|
| + new_capture(data_.u_position_register.reg,
|
| + data_.u_position_register.is_capture,
|
| + trace);
|
| + Trace new_trace = *trace;
|
| + new_trace.add_action(&new_capture);
|
| + on_success()->Emit(compiler, &new_trace);
|
| + break;
|
| + }
|
| + case INCREMENT_REGISTER: {
|
| + Trace::DeferredIncrementRegister
|
| + new_increment(data_.u_increment_register.reg);
|
| + Trace new_trace = *trace;
|
| + new_trace.add_action(&new_increment);
|
| + on_success()->Emit(compiler, &new_trace);
|
| + break;
|
| + }
|
| + case SET_REGISTER: {
|
| + Trace::DeferredSetRegister
|
| + new_set(data_.u_store_register.reg, data_.u_store_register.value);
|
| + Trace new_trace = *trace;
|
| + new_trace.add_action(&new_set);
|
| + on_success()->Emit(compiler, &new_trace);
|
| + break;
|
| + }
|
| + case CLEAR_CAPTURES: {
|
| + Trace::DeferredClearCaptures
|
| + new_capture(Interval(data_.u_clear_captures.range_from,
|
| + data_.u_clear_captures.range_to));
|
| + Trace new_trace = *trace;
|
| + new_trace.add_action(&new_capture);
|
| + on_success()->Emit(compiler, &new_trace);
|
| + break;
|
| + }
|
| + case BEGIN_SUBMATCH:
|
| + if (!trace->is_trivial()) {
|
| + trace->Flush(compiler, this);
|
| + } else {
|
| + assembler->WriteCurrentPositionToRegister(
|
| + data_.u_submatch.current_position_register, 0);
|
| + assembler->WriteStackPointerToRegister(
|
| + data_.u_submatch.stack_pointer_register);
|
| + on_success()->Emit(compiler, trace);
|
| + }
|
| + break;
|
| + case EMPTY_MATCH_CHECK: {
|
| + int start_pos_reg = data_.u_empty_match_check.start_register;
|
| + int stored_pos = 0;
|
| + int rep_reg = data_.u_empty_match_check.repetition_register;
|
| + bool has_minimum = (rep_reg != RegExpCompiler::kNoRegister);
|
| + bool know_dist = trace->GetStoredPosition(start_pos_reg, &stored_pos);
|
| + if (know_dist && !has_minimum && stored_pos == trace->cp_offset()) {
|
| + // If we know we haven't advanced and there is no minimum we
|
| + // can just backtrack immediately.
|
| + assembler->GoTo(trace->backtrack());
|
| + } else if (know_dist && stored_pos < trace->cp_offset()) {
|
| + // If we know we've advanced we can generate the continuation
|
| + // immediately.
|
| + on_success()->Emit(compiler, trace);
|
| + } else if (!trace->is_trivial()) {
|
| + trace->Flush(compiler, this);
|
| + } else {
|
| + Label skip_empty_check;
|
| + // If we have a minimum number of repetitions we check the current
|
| + // number first and skip the empty check if it's not enough.
|
| + if (has_minimum) {
|
| + int limit = data_.u_empty_match_check.repetition_limit;
|
| + assembler->IfRegisterLT(rep_reg, limit, &skip_empty_check);
|
| + }
|
| + // If the match is empty we bail out, otherwise we fall through
|
| + // to the on-success continuation.
|
| + assembler->IfRegisterEqPos(data_.u_empty_match_check.start_register,
|
| + trace->backtrack());
|
| + assembler->Bind(&skip_empty_check);
|
| + on_success()->Emit(compiler, trace);
|
| + }
|
| + break;
|
| + }
|
| + case POSITIVE_SUBMATCH_SUCCESS: {
|
| + if (!trace->is_trivial()) {
|
| + trace->Flush(compiler, this);
|
| + return;
|
| + }
|
| + assembler->ReadCurrentPositionFromRegister(
|
| + data_.u_submatch.current_position_register);
|
| + assembler->ReadStackPointerFromRegister(
|
| + data_.u_submatch.stack_pointer_register);
|
| + int clear_register_count = data_.u_submatch.clear_register_count;
|
| + if (clear_register_count == 0) {
|
| + on_success()->Emit(compiler, trace);
|
| + return;
|
| + }
|
| + int clear_registers_from = data_.u_submatch.clear_register_from;
|
| + Label clear_registers_backtrack;
|
| + Trace new_trace = *trace;
|
| + new_trace.set_backtrack(&clear_registers_backtrack);
|
| + on_success()->Emit(compiler, &new_trace);
|
| +
|
| + assembler->Bind(&clear_registers_backtrack);
|
| + int clear_registers_to = clear_registers_from + clear_register_count - 1;
|
| + assembler->ClearRegisters(clear_registers_from, clear_registers_to);
|
| +
|
| + DCHECK(trace->backtrack() == NULL);
|
| + assembler->Backtrack();
|
| + return;
|
| + }
|
| + default:
|
| + UNREACHABLE();
|
| + }
|
| +}
|
| +
|
| +
|
| +void BackReferenceNode::Emit(RegExpCompiler* compiler, Trace* trace) {
|
| + RegExpMacroAssembler* assembler = compiler->macro_assembler();
|
| + if (!trace->is_trivial()) {
|
| + trace->Flush(compiler, this);
|
| + return;
|
| + }
|
| +
|
| + LimitResult limit_result = LimitVersions(compiler, trace);
|
| + if (limit_result == DONE) return;
|
| + DCHECK(limit_result == CONTINUE);
|
| +
|
| + RecursionCheck rc(compiler);
|
| +
|
| + DCHECK_EQ(start_reg_ + 1, end_reg_);
|
| + if (compiler->ignore_case()) {
|
| + assembler->CheckNotBackReferenceIgnoreCase(start_reg_,
|
| + trace->backtrack());
|
| + } else {
|
| + assembler->CheckNotBackReference(start_reg_, trace->backtrack());
|
| + }
|
| + on_success()->Emit(compiler, trace);
|
| +}
|
| +
|
| +
|
| +// -------------------------------------------------------------------
|
| +// Dot/dotty output
|
| +
|
| +
|
| +#ifdef DEBUG
|
| +
|
| +
|
| +class DotPrinter: public NodeVisitor {
|
| + public:
|
| + DotPrinter(OStream& os, bool ignore_case) // NOLINT
|
| + : os_(os),
|
| + ignore_case_(ignore_case) {}
|
| + void PrintNode(const char* label, RegExpNode* node);
|
| + void Visit(RegExpNode* node);
|
| + void PrintAttributes(RegExpNode* from);
|
| + void PrintOnFailure(RegExpNode* from, RegExpNode* to);
|
| +#define DECLARE_VISIT(Type) \
|
| + virtual void Visit##Type(Type##Node* that);
|
| +FOR_EACH_NODE_TYPE(DECLARE_VISIT)
|
| +#undef DECLARE_VISIT
|
| + private:
|
| + OStream& os_;
|
| + bool ignore_case_;
|
| +};
|
| +
|
| +
|
| +void DotPrinter::PrintNode(const char* label, RegExpNode* node) {
|
| + os_ << "digraph G {\n graph [label=\"";
|
| + for (int i = 0; label[i]; i++) {
|
| + switch (label[i]) {
|
| + case '\\':
|
| + os_ << "\\\\";
|
| + break;
|
| + case '"':
|
| + os_ << "\"";
|
| + break;
|
| + default:
|
| + os_ << label[i];
|
| + break;
|
| + }
|
| + }
|
| + os_ << "\"];\n";
|
| + Visit(node);
|
| + os_ << "}" << endl;
|
| +}
|
| +
|
| +
|
| +void DotPrinter::Visit(RegExpNode* node) {
|
| + if (node->info()->visited) return;
|
| + node->info()->visited = true;
|
| + node->Accept(this);
|
| +}
|
| +
|
| +
|
| +void DotPrinter::PrintOnFailure(RegExpNode* from, RegExpNode* on_failure) {
|
| + os_ << " n" << from << " -> n" << on_failure << " [style=dotted];\n";
|
| + Visit(on_failure);
|
| +}
|
| +
|
| +
|
| +class TableEntryBodyPrinter {
|
| + public:
|
| + TableEntryBodyPrinter(OStream& os, ChoiceNode* choice) // NOLINT
|
| + : os_(os),
|
| + choice_(choice) {}
|
| + void Call(uc16 from, DispatchTable::Entry entry) {
|
| + OutSet* out_set = entry.out_set();
|
| + for (unsigned i = 0; i < OutSet::kFirstLimit; i++) {
|
| + if (out_set->Get(i)) {
|
| + os_ << " n" << choice() << ":s" << from << "o" << i << " -> n"
|
| + << choice()->alternatives()->at(i).node() << ";\n";
|
| + }
|
| + }
|
| + }
|
| + private:
|
| + ChoiceNode* choice() { return choice_; }
|
| + OStream& os_;
|
| + ChoiceNode* choice_;
|
| +};
|
| +
|
| +
|
| +class TableEntryHeaderPrinter {
|
| + public:
|
| + explicit TableEntryHeaderPrinter(OStream& os) // NOLINT
|
| + : first_(true),
|
| + os_(os) {}
|
| + void Call(uc16 from, DispatchTable::Entry entry) {
|
| + if (first_) {
|
| + first_ = false;
|
| + } else {
|
| + os_ << "|";
|
| + }
|
| + os_ << "{\\" << AsUC16(from) << "-\\" << AsUC16(entry.to()) << "|{";
|
| + OutSet* out_set = entry.out_set();
|
| + int priority = 0;
|
| + for (unsigned i = 0; i < OutSet::kFirstLimit; i++) {
|
| + if (out_set->Get(i)) {
|
| + if (priority > 0) os_ << "|";
|
| + os_ << "<s" << from << "o" << i << "> " << priority;
|
| + priority++;
|
| + }
|
| + }
|
| + os_ << "}}";
|
| + }
|
| +
|
| + private:
|
| + bool first_;
|
| + OStream& os_;
|
| +};
|
| +
|
| +
|
| +class AttributePrinter {
|
| + public:
|
| + explicit AttributePrinter(OStream& os) // NOLINT
|
| + : os_(os),
|
| + first_(true) {}
|
| + void PrintSeparator() {
|
| + if (first_) {
|
| + first_ = false;
|
| + } else {
|
| + os_ << "|";
|
| + }
|
| + }
|
| + void PrintBit(const char* name, bool value) {
|
| + if (!value) return;
|
| + PrintSeparator();
|
| + os_ << "{" << name << "}";
|
| + }
|
| + void PrintPositive(const char* name, int value) {
|
| + if (value < 0) return;
|
| + PrintSeparator();
|
| + os_ << "{" << name << "|" << value << "}";
|
| + }
|
| +
|
| + private:
|
| + OStream& os_;
|
| + bool first_;
|
| +};
|
| +
|
| +
|
| +void DotPrinter::PrintAttributes(RegExpNode* that) {
|
| + os_ << " a" << that << " [shape=Mrecord, color=grey, fontcolor=grey, "
|
| + << "margin=0.1, fontsize=10, label=\"{";
|
| + AttributePrinter printer(os_);
|
| + NodeInfo* info = that->info();
|
| + printer.PrintBit("NI", info->follows_newline_interest);
|
| + printer.PrintBit("WI", info->follows_word_interest);
|
| + printer.PrintBit("SI", info->follows_start_interest);
|
| + Label* label = that->label();
|
| + if (label->is_bound())
|
| + printer.PrintPositive("@", label->pos());
|
| + os_ << "}\"];\n"
|
| + << " a" << that << " -> n" << that
|
| + << " [style=dashed, color=grey, arrowhead=none];\n";
|
| +}
|
| +
|
| +
|
| +static const bool kPrintDispatchTable = false;
|
| +void DotPrinter::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();
|
| + }
|
| + }
|
| + for (int i = 0; i < that->alternatives()->length(); i++) {
|
| + GuardedAlternative alt = that->alternatives()->at(i);
|
| + alt.node()->Accept(this);
|
| + }
|
| +}
|
| +
|
| +
|
| +void DotPrinter::VisitText(TextNode* that) {
|
| + Zone* zone = that->zone();
|
| + os_ << " n" << that << " [label=\"";
|
| + for (int i = 0; i < that->elements()->length(); i++) {
|
| + if (i > 0) os_ << " ";
|
| + TextElement elm = that->elements()->at(i);
|
| + switch (elm.text_type()) {
|
| + case TextElement::ATOM: {
|
| + Vector<const uc16> data = elm.atom()->data();
|
| + for (int i = 0; i < data.length(); i++) {
|
| + os_ << static_cast<char>(data[i]);
|
| + }
|
| + break;
|
| + }
|
| + case TextElement::CHAR_CLASS: {
|
| + RegExpCharacterClass* node = elm.char_class();
|
| + os_ << "[";
|
| + if (node->is_negated()) os_ << "^";
|
| + for (int j = 0; j < node->ranges(zone)->length(); j++) {
|
| + CharacterRange range = node->ranges(zone)->at(j);
|
| + os_ << AsUC16(range.from()) << "-" << AsUC16(range.to());
|
| + }
|
| + os_ << "]";
|
| + break;
|
| + }
|
| + default:
|
| + UNREACHABLE();
|
| + }
|
| + }
|
| + os_ << "\", shape=box, peripheries=2];\n";
|
| + PrintAttributes(that);
|
| + os_ << " n" << that << " -> n" << that->on_success() << ";\n";
|
| + Visit(that->on_success());
|
| +}
|
| +
|
| +
|
| +void DotPrinter::VisitBackReference(BackReferenceNode* that) {
|
| + os_ << " n" << that << " [label=\"$" << that->start_register() << "..$"
|
| + << that->end_register() << "\", shape=doubleoctagon];\n";
|
| + PrintAttributes(that);
|
| + os_ << " n" << that << " -> n" << that->on_success() << ";\n";
|
| + Visit(that->on_success());
|
| +}
|
| +
|
| +
|
| +void DotPrinter::VisitEnd(EndNode* that) {
|
| + os_ << " n" << that << " [style=bold, shape=point];\n";
|
| + PrintAttributes(that);
|
| +}
|
| +
|
| +
|
| +void DotPrinter::VisitAssertion(AssertionNode* that) {
|
| + os_ << " n" << that << " [";
|
| + switch (that->assertion_type()) {
|
| + case AssertionNode::AT_END:
|
| + os_ << "label=\"$\", shape=septagon";
|
| + break;
|
| + case AssertionNode::AT_START:
|
| + os_ << "label=\"^\", shape=septagon";
|
| + break;
|
| + case AssertionNode::AT_BOUNDARY:
|
| + os_ << "label=\"\\b\", shape=septagon";
|
| + break;
|
| + case AssertionNode::AT_NON_BOUNDARY:
|
| + os_ << "label=\"\\B\", shape=septagon";
|
| + break;
|
| + case AssertionNode::AFTER_NEWLINE:
|
| + os_ << "label=\"(?<=\\n)\", shape=septagon";
|
| + break;
|
| + }
|
| + os_ << "];\n";
|
| + PrintAttributes(that);
|
| + RegExpNode* successor = that->on_success();
|
| + os_ << " n" << that << " -> n" << successor << ";\n";
|
| + Visit(successor);
|
| +}
|
| +
|
| +
|
| +void DotPrinter::VisitAction(ActionNode* that) {
|
| + os_ << " n" << that << " [";
|
| + switch (that->action_type_) {
|
| + case ActionNode::SET_REGISTER:
|
| + os_ << "label=\"$" << that->data_.u_store_register.reg
|
| + << ":=" << that->data_.u_store_register.value << "\", shape=octagon";
|
| + break;
|
| + case ActionNode::INCREMENT_REGISTER:
|
| + os_ << "label=\"$" << that->data_.u_increment_register.reg
|
| + << "++\", shape=octagon";
|
| + break;
|
| + case ActionNode::STORE_POSITION:
|
| + os_ << "label=\"$" << that->data_.u_position_register.reg
|
| + << ":=$pos\", shape=octagon";
|
| + break;
|
| + case ActionNode::BEGIN_SUBMATCH:
|
| + os_ << "label=\"$" << that->data_.u_submatch.current_position_register
|
| + << ":=$pos,begin\", shape=septagon";
|
| + break;
|
| + case ActionNode::POSITIVE_SUBMATCH_SUCCESS:
|
| + os_ << "label=\"escape\", shape=septagon";
|
| + break;
|
| + case ActionNode::EMPTY_MATCH_CHECK:
|
| + os_ << "label=\"$" << that->data_.u_empty_match_check.start_register
|
| + << "=$pos?,$" << that->data_.u_empty_match_check.repetition_register
|
| + << "<" << that->data_.u_empty_match_check.repetition_limit
|
| + << "?\", shape=septagon";
|
| + break;
|
| + case ActionNode::CLEAR_CAPTURES: {
|
| + os_ << "label=\"clear $" << that->data_.u_clear_captures.range_from
|
| + << " to $" << that->data_.u_clear_captures.range_to
|
| + << "\", shape=septagon";
|
| + break;
|
| + }
|
| + }
|
| + os_ << "];\n";
|
| + PrintAttributes(that);
|
| + RegExpNode* successor = that->on_success();
|
| + os_ << " n" << that << " -> n" << successor << ";\n";
|
| + Visit(successor);
|
| +}
|
| +
|
| +
|
| +class DispatchTableDumper {
|
| + public:
|
| + explicit DispatchTableDumper(OStream& os) : os_(os) {}
|
| + void Call(uc16 key, DispatchTable::Entry entry);
|
| + private:
|
| + OStream& os_;
|
| +};
|
| +
|
| +
|
| +void DispatchTableDumper::Call(uc16 key, DispatchTable::Entry entry) {
|
| + os_ << "[" << AsUC16(key) << "-" << AsUC16(entry.to()) << "]: {";
|
| + OutSet* set = entry.out_set();
|
| + bool first = true;
|
| + for (unsigned i = 0; i < OutSet::kFirstLimit; i++) {
|
| + if (set->Get(i)) {
|
| + if (first) {
|
| + first = false;
|
| + } else {
|
| + os_ << ", ";
|
| + }
|
| + os_ << i;
|
| + }
|
| + }
|
| + os_ << "}\n";
|
| +}
|
| +
|
| +
|
| +void DispatchTable::Dump() {
|
| + OFStream os(stderr);
|
| + DispatchTableDumper dumper(os);
|
| + tree()->ForEach(&dumper);
|
| +}
|
| +
|
| +
|
| +void RegExpEngine::DotPrint(const char* label,
|
| + RegExpNode* node,
|
| + bool ignore_case) {
|
| + OFStream os(stdout);
|
| + DotPrinter printer(os, ignore_case);
|
| + printer.PrintNode(label, node);
|
| +}
|
| +
|
| +
|
| +#endif // DEBUG
|
| +
|
| +
|
| +// -------------------------------------------------------------------
|
| +// Tree to graph conversion
|
| +
|
| +RegExpNode* RegExpAtom::ToNode(RegExpCompiler* compiler,
|
| + RegExpNode* on_success) {
|
| + ZoneList<TextElement>* elms =
|
| + new(compiler->zone()) ZoneList<TextElement>(1, compiler->zone());
|
| + elms->Add(TextElement::Atom(this), compiler->zone());
|
| + return new(compiler->zone()) TextNode(elms, on_success);
|
| +}
|
| +
|
| +
|
| +RegExpNode* RegExpText::ToNode(RegExpCompiler* compiler,
|
| + RegExpNode* on_success) {
|
| + return new(compiler->zone()) TextNode(elements(), on_success);
|
| +}
|
| +
|
| +
|
| +static bool CompareInverseRanges(ZoneList<CharacterRange>* ranges,
|
| + const int* special_class,
|
| + int length) {
|
| + length--; // Remove final 0x10000.
|
| + DCHECK(special_class[length] == 0x10000);
|
| + DCHECK(ranges->length() != 0);
|
| + DCHECK(length != 0);
|
| + DCHECK(special_class[0] != 0);
|
| + if (ranges->length() != (length >> 1) + 1) {
|
| + return false;
|
| + }
|
| + CharacterRange range = ranges->at(0);
|
| + if (range.from() != 0) {
|
| + return false;
|
| + }
|
| + for (int i = 0; i < length; i += 2) {
|
| + if (special_class[i] != (range.to() + 1)) {
|
| + return false;
|
| + }
|
| + range = ranges->at((i >> 1) + 1);
|
| + if (special_class[i+1] != range.from()) {
|
| + return false;
|
| + }
|
| + }
|
| + if (range.to() != 0xffff) {
|
| + return false;
|
| + }
|
| + return true;
|
| +}
|
| +
|
| +
|
| +static bool CompareRanges(ZoneList<CharacterRange>* ranges,
|
| + const int* special_class,
|
| + int length) {
|
| + length--; // Remove final 0x10000.
|
| + DCHECK(special_class[length] == 0x10000);
|
| + if (ranges->length() * 2 != length) {
|
| + return false;
|
| + }
|
| + for (int i = 0; i < length; i += 2) {
|
| + CharacterRange range = ranges->at(i >> 1);
|
| + if (range.from() != special_class[i] ||
|
| + range.to() != special_class[i + 1] - 1) {
|
| + return false;
|
| + }
|
| + }
|
| + return true;
|
| +}
|
| +
|
| +
|
| +bool RegExpCharacterClass::is_standard(Zone* zone) {
|
| + // TODO(lrn): Remove need for this function, by not throwing away information
|
| + // along the way.
|
| + if (is_negated_) {
|
| + return false;
|
| + }
|
| + if (set_.is_standard()) {
|
| + return true;
|
| + }
|
| + if (CompareRanges(set_.ranges(zone), kSpaceRanges, kSpaceRangeCount)) {
|
| + set_.set_standard_set_type('s');
|
| + return true;
|
| + }
|
| + if (CompareInverseRanges(set_.ranges(zone), kSpaceRanges, kSpaceRangeCount)) {
|
| + set_.set_standard_set_type('S');
|
| + return true;
|
| + }
|
| + if (CompareInverseRanges(set_.ranges(zone),
|
| + kLineTerminatorRanges,
|
| + kLineTerminatorRangeCount)) {
|
| + set_.set_standard_set_type('.');
|
| + return true;
|
| + }
|
| + if (CompareRanges(set_.ranges(zone),
|
| + kLineTerminatorRanges,
|
| + kLineTerminatorRangeCount)) {
|
| + set_.set_standard_set_type('n');
|
| + return true;
|
| + }
|
| + if (CompareRanges(set_.ranges(zone), kWordRanges, kWordRangeCount)) {
|
| + set_.set_standard_set_type('w');
|
| + return true;
|
| + }
|
| + if (CompareInverseRanges(set_.ranges(zone), kWordRanges, kWordRangeCount)) {
|
| + set_.set_standard_set_type('W');
|
| + return true;
|
| + }
|
| + return false;
|
| +}
|
| +
|
| +
|
| +RegExpNode* RegExpCharacterClass::ToNode(RegExpCompiler* compiler,
|
| + RegExpNode* on_success) {
|
| + return new(compiler->zone()) TextNode(this, on_success);
|
| +}
|
| +
|
| +
|
| +RegExpNode* RegExpDisjunction::ToNode(RegExpCompiler* compiler,
|
| + RegExpNode* on_success) {
|
| + ZoneList<RegExpTree*>* alternatives = this->alternatives();
|
| + int length = alternatives->length();
|
| + ChoiceNode* result =
|
| + new(compiler->zone()) ChoiceNode(length, compiler->zone());
|
| + for (int i = 0; i < length; i++) {
|
| + GuardedAlternative alternative(alternatives->at(i)->ToNode(compiler,
|
| + on_success));
|
| + result->AddAlternative(alternative);
|
| + }
|
| + return result;
|
| +}
|
| +
|
| +
|
| +RegExpNode* RegExpQuantifier::ToNode(RegExpCompiler* compiler,
|
| + RegExpNode* on_success) {
|
| + return ToNode(min(),
|
| + max(),
|
| + is_greedy(),
|
| + body(),
|
| + compiler,
|
| + on_success);
|
| +}
|
| +
|
| +
|
| +// Scoped object to keep track of how much we unroll quantifier loops in the
|
| +// regexp graph generator.
|
| +class RegExpExpansionLimiter {
|
| + public:
|
| + static const int kMaxExpansionFactor = 6;
|
| + RegExpExpansionLimiter(RegExpCompiler* compiler, int factor)
|
| + : compiler_(compiler),
|
| + saved_expansion_factor_(compiler->current_expansion_factor()),
|
| + ok_to_expand_(saved_expansion_factor_ <= kMaxExpansionFactor) {
|
| + DCHECK(factor > 0);
|
| + if (ok_to_expand_) {
|
| + if (factor > kMaxExpansionFactor) {
|
| + // Avoid integer overflow of the current expansion factor.
|
| + ok_to_expand_ = false;
|
| + compiler->set_current_expansion_factor(kMaxExpansionFactor + 1);
|
| + } else {
|
| + int new_factor = saved_expansion_factor_ * factor;
|
| + ok_to_expand_ = (new_factor <= kMaxExpansionFactor);
|
| + compiler->set_current_expansion_factor(new_factor);
|
| + }
|
| + }
|
| + }
|
| +
|
| + ~RegExpExpansionLimiter() {
|
| + compiler_->set_current_expansion_factor(saved_expansion_factor_);
|
| + }
|
| +
|
| + bool ok_to_expand() { return ok_to_expand_; }
|
| +
|
| + private:
|
| + RegExpCompiler* compiler_;
|
| + int saved_expansion_factor_;
|
| + bool ok_to_expand_;
|
| +
|
| + DISALLOW_IMPLICIT_CONSTRUCTORS(RegExpExpansionLimiter);
|
| +};
|
| +
|
| +
|
| +RegExpNode* RegExpQuantifier::ToNode(int min,
|
| + int max,
|
| + bool is_greedy,
|
| + RegExpTree* body,
|
| + RegExpCompiler* compiler,
|
| + RegExpNode* on_success,
|
| + bool not_at_start) {
|
| + // x{f, t} becomes this:
|
| + //
|
| + // (r++)<-.
|
| + // | `
|
| + // | (x)
|
| + // v ^
|
| + // (r=0)-->(?)---/ [if r < t]
|
| + // |
|
| + // [if r >= f] \----> ...
|
| + //
|
| +
|
| + // 15.10.2.5 RepeatMatcher algorithm.
|
| + // The parser has already eliminated the case where max is 0. In the case
|
| + // where max_match is zero the parser has removed the quantifier if min was
|
| + // > 0 and removed the atom if min was 0. See AddQuantifierToAtom.
|
| +
|
| + // If we know that we cannot match zero length then things are a little
|
| + // simpler since we don't need to make the special zero length match check
|
| + // from step 2.1. If the min and max are small we can unroll a little in
|
| + // this case.
|
| + static const int kMaxUnrolledMinMatches = 3; // Unroll (foo)+ and (foo){3,}
|
| + static const int kMaxUnrolledMaxMatches = 3; // Unroll (foo)? and (foo){x,3}
|
| + if (max == 0) return on_success; // This can happen due to recursion.
|
| + bool body_can_be_empty = (body->min_match() == 0);
|
| + int body_start_reg = RegExpCompiler::kNoRegister;
|
| + Interval capture_registers = body->CaptureRegisters();
|
| + bool needs_capture_clearing = !capture_registers.is_empty();
|
| + Zone* zone = compiler->zone();
|
| +
|
| + if (body_can_be_empty) {
|
| + body_start_reg = compiler->AllocateRegister();
|
| + } else if (FLAG_regexp_optimization && !needs_capture_clearing) {
|
| + // Only unroll if there are no captures and the body can't be
|
| + // empty.
|
| + {
|
| + RegExpExpansionLimiter limiter(
|
| + compiler, min + ((max != min) ? 1 : 0));
|
| + if (min > 0 && min <= kMaxUnrolledMinMatches && limiter.ok_to_expand()) {
|
| + int new_max = (max == kInfinity) ? max : max - min;
|
| + // Recurse once to get the loop or optional matches after the fixed
|
| + // ones.
|
| + RegExpNode* answer = ToNode(
|
| + 0, new_max, is_greedy, body, compiler, on_success, true);
|
| + // Unroll the forced matches from 0 to min. This can cause chains of
|
| + // TextNodes (which the parser does not generate). These should be
|
| + // combined if it turns out they hinder good code generation.
|
| + for (int i = 0; i < min; i++) {
|
| + answer = body->ToNode(compiler, answer);
|
| + }
|
| + return answer;
|
| + }
|
| + }
|
| + if (max <= kMaxUnrolledMaxMatches && min == 0) {
|
| + DCHECK(max > 0); // Due to the 'if' above.
|
| + RegExpExpansionLimiter limiter(compiler, max);
|
| + if (limiter.ok_to_expand()) {
|
| + // Unroll the optional matches up to max.
|
| + RegExpNode* answer = on_success;
|
| + for (int i = 0; i < max; i++) {
|
| + ChoiceNode* alternation = new(zone) ChoiceNode(2, zone);
|
| + if (is_greedy) {
|
| + alternation->AddAlternative(
|
| + GuardedAlternative(body->ToNode(compiler, answer)));
|
| + alternation->AddAlternative(GuardedAlternative(on_success));
|
| + } else {
|
| + alternation->AddAlternative(GuardedAlternative(on_success));
|
| + alternation->AddAlternative(
|
| + GuardedAlternative(body->ToNode(compiler, answer)));
|
| + }
|
| + answer = alternation;
|
| + if (not_at_start) alternation->set_not_at_start();
|
| + }
|
| + return answer;
|
| + }
|
| + }
|
| + }
|
| + bool has_min = min > 0;
|
| + bool has_max = max < RegExpTree::kInfinity;
|
| + bool needs_counter = has_min || has_max;
|
| + int reg_ctr = needs_counter
|
| + ? compiler->AllocateRegister()
|
| + : RegExpCompiler::kNoRegister;
|
| + LoopChoiceNode* center = new(zone) LoopChoiceNode(body->min_match() == 0,
|
| + zone);
|
| + if (not_at_start) center->set_not_at_start();
|
| + RegExpNode* loop_return = needs_counter
|
| + ? static_cast<RegExpNode*>(ActionNode::IncrementRegister(reg_ctr, center))
|
| + : static_cast<RegExpNode*>(center);
|
| + if (body_can_be_empty) {
|
| + // If the body can be empty we need to check if it was and then
|
| + // backtrack.
|
| + loop_return = ActionNode::EmptyMatchCheck(body_start_reg,
|
| + reg_ctr,
|
| + min,
|
| + loop_return);
|
| + }
|
| + RegExpNode* body_node = body->ToNode(compiler, loop_return);
|
| + if (body_can_be_empty) {
|
| + // If the body can be empty we need to store the start position
|
| + // so we can bail out if it was empty.
|
| + body_node = ActionNode::StorePosition(body_start_reg, false, body_node);
|
| + }
|
| + if (needs_capture_clearing) {
|
| + // Before entering the body of this loop we need to clear captures.
|
| + body_node = ActionNode::ClearCaptures(capture_registers, body_node);
|
| + }
|
| + GuardedAlternative body_alt(body_node);
|
| + if (has_max) {
|
| + Guard* body_guard =
|
| + new(zone) Guard(reg_ctr, Guard::LT, max);
|
| + body_alt.AddGuard(body_guard, zone);
|
| + }
|
| + GuardedAlternative rest_alt(on_success);
|
| + if (has_min) {
|
| + Guard* rest_guard = new(compiler->zone()) Guard(reg_ctr, Guard::GEQ, min);
|
| + rest_alt.AddGuard(rest_guard, zone);
|
| + }
|
| + if (is_greedy) {
|
| + center->AddLoopAlternative(body_alt);
|
| + center->AddContinueAlternative(rest_alt);
|
| + } else {
|
| + center->AddContinueAlternative(rest_alt);
|
| + center->AddLoopAlternative(body_alt);
|
| + }
|
| + if (needs_counter) {
|
| + return ActionNode::SetRegister(reg_ctr, 0, center);
|
| + } else {
|
| + return center;
|
| + }
|
| +}
|
| +
|
| +
|
| +RegExpNode* RegExpAssertion::ToNode(RegExpCompiler* compiler,
|
| + RegExpNode* on_success) {
|
| + NodeInfo info;
|
| + Zone* zone = compiler->zone();
|
| +
|
| + switch (assertion_type()) {
|
| + case START_OF_LINE:
|
| + return AssertionNode::AfterNewline(on_success);
|
| + case START_OF_INPUT:
|
| + return AssertionNode::AtStart(on_success);
|
| + case BOUNDARY:
|
| + return AssertionNode::AtBoundary(on_success);
|
| + case NON_BOUNDARY:
|
| + return AssertionNode::AtNonBoundary(on_success);
|
| + case END_OF_INPUT:
|
| + return AssertionNode::AtEnd(on_success);
|
| + case END_OF_LINE: {
|
| + // Compile $ in multiline regexps as an alternation with a positive
|
| + // lookahead in one side and an end-of-input on the other side.
|
| + // We need two registers for the lookahead.
|
| + int stack_pointer_register = compiler->AllocateRegister();
|
| + int position_register = compiler->AllocateRegister();
|
| + // The ChoiceNode to distinguish between a newline and end-of-input.
|
| + ChoiceNode* result = new(zone) ChoiceNode(2, zone);
|
| + // Create a newline atom.
|
| + ZoneList<CharacterRange>* newline_ranges =
|
| + new(zone) ZoneList<CharacterRange>(3, zone);
|
| + CharacterRange::AddClassEscape('n', newline_ranges, zone);
|
| + RegExpCharacterClass* newline_atom = new(zone) RegExpCharacterClass('n');
|
| + TextNode* newline_matcher = new(zone) TextNode(
|
| + newline_atom,
|
| + ActionNode::PositiveSubmatchSuccess(stack_pointer_register,
|
| + position_register,
|
| + 0, // No captures inside.
|
| + -1, // Ignored if no captures.
|
| + on_success));
|
| + // Create an end-of-input matcher.
|
| + RegExpNode* end_of_line = ActionNode::BeginSubmatch(
|
| + stack_pointer_register,
|
| + position_register,
|
| + newline_matcher);
|
| + // Add the two alternatives to the ChoiceNode.
|
| + GuardedAlternative eol_alternative(end_of_line);
|
| + result->AddAlternative(eol_alternative);
|
| + GuardedAlternative end_alternative(AssertionNode::AtEnd(on_success));
|
| + result->AddAlternative(end_alternative);
|
| + return result;
|
| + }
|
| + default:
|
| + UNREACHABLE();
|
| + }
|
| + return on_success;
|
| +}
|
| +
|
| +
|
| +RegExpNode* RegExpBackReference::ToNode(RegExpCompiler* compiler,
|
| + RegExpNode* on_success) {
|
| + return new(compiler->zone())
|
| + BackReferenceNode(RegExpCapture::StartRegister(index()),
|
| + RegExpCapture::EndRegister(index()),
|
| + on_success);
|
| +}
|
| +
|
| +
|
| +RegExpNode* RegExpEmpty::ToNode(RegExpCompiler* compiler,
|
| + RegExpNode* on_success) {
|
| + return on_success;
|
| +}
|
| +
|
| +
|
| +RegExpNode* RegExpLookahead::ToNode(RegExpCompiler* compiler,
|
| + RegExpNode* on_success) {
|
| + int stack_pointer_register = compiler->AllocateRegister();
|
| + int position_register = compiler->AllocateRegister();
|
| +
|
| + const int registers_per_capture = 2;
|
| + const int register_of_first_capture = 2;
|
| + int register_count = capture_count_ * registers_per_capture;
|
| + int register_start =
|
| + register_of_first_capture + capture_from_ * registers_per_capture;
|
| +
|
| + RegExpNode* success;
|
| + if (is_positive()) {
|
| + RegExpNode* node = ActionNode::BeginSubmatch(
|
| + stack_pointer_register,
|
| + position_register,
|
| + body()->ToNode(
|
| + compiler,
|
| + ActionNode::PositiveSubmatchSuccess(stack_pointer_register,
|
| + position_register,
|
| + register_count,
|
| + register_start,
|
| + on_success)));
|
| + return node;
|
| + } else {
|
| + // We use a ChoiceNode for a negative lookahead because it has most of
|
| + // the characteristics we need. It has the body of the lookahead as its
|
| + // first alternative and the expression after the lookahead of the second
|
| + // alternative. If the first alternative succeeds then the
|
| + // NegativeSubmatchSuccess will unwind the stack including everything the
|
| + // choice node set up and backtrack. If the first alternative fails then
|
| + // the second alternative is tried, which is exactly the desired result
|
| + // for a negative lookahead. The NegativeLookaheadChoiceNode is a special
|
| + // ChoiceNode that knows to ignore the first exit when calculating quick
|
| + // checks.
|
| + Zone* zone = compiler->zone();
|
| +
|
| + GuardedAlternative body_alt(
|
| + body()->ToNode(
|
| + compiler,
|
| + success = new(zone) NegativeSubmatchSuccess(stack_pointer_register,
|
| + position_register,
|
| + register_count,
|
| + register_start,
|
| + zone)));
|
| + ChoiceNode* choice_node =
|
| + new(zone) NegativeLookaheadChoiceNode(body_alt,
|
| + GuardedAlternative(on_success),
|
| + zone);
|
| + return ActionNode::BeginSubmatch(stack_pointer_register,
|
| + position_register,
|
| + choice_node);
|
| + }
|
| +}
|
| +
|
| +
|
| +RegExpNode* RegExpCapture::ToNode(RegExpCompiler* compiler,
|
| + RegExpNode* on_success) {
|
| + return ToNode(body(), index(), compiler, on_success);
|
| +}
|
| +
|
| +
|
| +RegExpNode* RegExpCapture::ToNode(RegExpTree* body,
|
| + int index,
|
| + RegExpCompiler* compiler,
|
| + RegExpNode* on_success) {
|
| + int start_reg = RegExpCapture::StartRegister(index);
|
| + int end_reg = RegExpCapture::EndRegister(index);
|
| + RegExpNode* store_end = ActionNode::StorePosition(end_reg, true, on_success);
|
| + RegExpNode* body_node = body->ToNode(compiler, store_end);
|
| + return ActionNode::StorePosition(start_reg, true, body_node);
|
| +}
|
| +
|
| +
|
| +RegExpNode* RegExpAlternative::ToNode(RegExpCompiler* compiler,
|
| + RegExpNode* on_success) {
|
| + ZoneList<RegExpTree*>* children = nodes();
|
| + RegExpNode* current = on_success;
|
| + for (int i = children->length() - 1; i >= 0; i--) {
|
| + current = children->at(i)->ToNode(compiler, current);
|
| + }
|
| + return current;
|
| +}
|
| +
|
| +
|
| +static void AddClass(const int* elmv,
|
| + int elmc,
|
| + ZoneList<CharacterRange>* ranges,
|
| + Zone* zone) {
|
| + elmc--;
|
| + DCHECK(elmv[elmc] == 0x10000);
|
| + for (int i = 0; i < elmc; i += 2) {
|
| + DCHECK(elmv[i] < elmv[i + 1]);
|
| + ranges->Add(CharacterRange(elmv[i], elmv[i + 1] - 1), zone);
|
| + }
|
| +}
|
| +
|
| +
|
| +static void AddClassNegated(const int *elmv,
|
| + int elmc,
|
| + ZoneList<CharacterRange>* ranges,
|
| + Zone* zone) {
|
| + elmc--;
|
| + DCHECK(elmv[elmc] == 0x10000);
|
| + DCHECK(elmv[0] != 0x0000);
|
| + DCHECK(elmv[elmc-1] != String::kMaxUtf16CodeUnit);
|
| + uc16 last = 0x0000;
|
| + for (int i = 0; i < elmc; i += 2) {
|
| + DCHECK(last <= elmv[i] - 1);
|
| + DCHECK(elmv[i] < elmv[i + 1]);
|
| + ranges->Add(CharacterRange(last, elmv[i] - 1), zone);
|
| + last = elmv[i + 1];
|
| + }
|
| + ranges->Add(CharacterRange(last, String::kMaxUtf16CodeUnit), zone);
|
| +}
|
| +
|
| +
|
| +void CharacterRange::AddClassEscape(uc16 type,
|
| + ZoneList<CharacterRange>* ranges,
|
| + Zone* zone) {
|
| + switch (type) {
|
| + case 's':
|
| + AddClass(kSpaceRanges, kSpaceRangeCount, ranges, zone);
|
| + break;
|
| + case 'S':
|
| + AddClassNegated(kSpaceRanges, kSpaceRangeCount, ranges, zone);
|
| + break;
|
| + case 'w':
|
| + AddClass(kWordRanges, kWordRangeCount, ranges, zone);
|
| + break;
|
| + case 'W':
|
| + AddClassNegated(kWordRanges, kWordRangeCount, ranges, zone);
|
| + break;
|
| + case 'd':
|
| + AddClass(kDigitRanges, kDigitRangeCount, ranges, zone);
|
| + break;
|
| + case 'D':
|
| + AddClassNegated(kDigitRanges, kDigitRangeCount, ranges, zone);
|
| + break;
|
| + case '.':
|
| + AddClassNegated(kLineTerminatorRanges,
|
| + kLineTerminatorRangeCount,
|
| + ranges,
|
| + zone);
|
| + break;
|
| + // This is not a character range as defined by the spec but a
|
| + // convenient shorthand for a character class that matches any
|
| + // character.
|
| + case '*':
|
| + ranges->Add(CharacterRange::Everything(), zone);
|
| + break;
|
| + // This is the set of characters matched by the $ and ^ symbols
|
| + // in multiline mode.
|
| + case 'n':
|
| + AddClass(kLineTerminatorRanges,
|
| + kLineTerminatorRangeCount,
|
| + ranges,
|
| + zone);
|
| + break;
|
| + default:
|
| + UNREACHABLE();
|
| + }
|
| +}
|
| +
|
| +
|
| +Vector<const int> CharacterRange::GetWordBounds() {
|
| + return Vector<const int>(kWordRanges, kWordRangeCount - 1);
|
| +}
|
| +
|
| +
|
| +class CharacterRangeSplitter {
|
| + public:
|
| + CharacterRangeSplitter(ZoneList<CharacterRange>** included,
|
| + ZoneList<CharacterRange>** excluded,
|
| + Zone* zone)
|
| + : included_(included),
|
| + excluded_(excluded),
|
| + zone_(zone) { }
|
| + void Call(uc16 from, DispatchTable::Entry entry);
|
| +
|
| + static const int kInBase = 0;
|
| + static const int kInOverlay = 1;
|
| +
|
| + private:
|
| + ZoneList<CharacterRange>** included_;
|
| + ZoneList<CharacterRange>** excluded_;
|
| + Zone* zone_;
|
| +};
|
| +
|
| +
|
| +void CharacterRangeSplitter::Call(uc16 from, DispatchTable::Entry entry) {
|
| + if (!entry.out_set()->Get(kInBase)) return;
|
| + ZoneList<CharacterRange>** target = entry.out_set()->Get(kInOverlay)
|
| + ? included_
|
| + : excluded_;
|
| + if (*target == NULL) *target = new(zone_) ZoneList<CharacterRange>(2, zone_);
|
| + (*target)->Add(CharacterRange(entry.from(), entry.to()), zone_);
|
| +}
|
| +
|
| +
|
| +void CharacterRange::Split(ZoneList<CharacterRange>* base,
|
| + Vector<const int> overlay,
|
| + ZoneList<CharacterRange>** included,
|
| + ZoneList<CharacterRange>** excluded,
|
| + Zone* zone) {
|
| + DCHECK_EQ(NULL, *included);
|
| + DCHECK_EQ(NULL, *excluded);
|
| + DispatchTable table(zone);
|
| + for (int i = 0; i < base->length(); i++)
|
| + table.AddRange(base->at(i), CharacterRangeSplitter::kInBase, zone);
|
| + for (int i = 0; i < overlay.length(); i += 2) {
|
| + table.AddRange(CharacterRange(overlay[i], overlay[i + 1] - 1),
|
| + CharacterRangeSplitter::kInOverlay, zone);
|
| + }
|
| + CharacterRangeSplitter callback(included, excluded, zone);
|
| + table.ForEach(&callback);
|
| +}
|
| +
|
| +
|
| +void CharacterRange::AddCaseEquivalents(ZoneList<CharacterRange>* ranges,
|
| + bool is_one_byte, Zone* zone) {
|
| + Isolate* isolate = zone->isolate();
|
| + uc16 bottom = from();
|
| + uc16 top = to();
|
| + if (is_one_byte && !RangeContainsLatin1Equivalents(*this)) {
|
| + if (bottom > String::kMaxOneByteCharCode) return;
|
| + if (top > String::kMaxOneByteCharCode) top = String::kMaxOneByteCharCode;
|
| + }
|
| + unibrow::uchar chars[unibrow::Ecma262UnCanonicalize::kMaxWidth];
|
| + if (top == bottom) {
|
| + // If this is a singleton we just expand the one character.
|
| + int length = isolate->jsregexp_uncanonicalize()->get(bottom, '\0', chars);
|
| + for (int i = 0; i < length; i++) {
|
| + uc32 chr = chars[i];
|
| + if (chr != bottom) {
|
| + ranges->Add(CharacterRange::Singleton(chars[i]), zone);
|
| + }
|
| + }
|
| + } else {
|
| + // If this is a range we expand the characters block by block,
|
| + // expanding contiguous subranges (blocks) one at a time.
|
| + // The approach is as follows. For a given start character we
|
| + // look up the remainder of the block that contains it (represented
|
| + // by the end point), for instance we find 'z' if the character
|
| + // is 'c'. A block is characterized by the property
|
| + // that all characters uncanonicalize in the same way, except that
|
| + // each entry in the result is incremented by the distance from the first
|
| + // element. So a-z is a block because 'a' uncanonicalizes to ['a', 'A'] and
|
| + // the k'th letter uncanonicalizes to ['a' + k, 'A' + k].
|
| + // Once we've found the end point we look up its uncanonicalization
|
| + // and produce a range for each element. For instance for [c-f]
|
| + // we look up ['z', 'Z'] and produce [c-f] and [C-F]. We then only
|
| + // add a range if it is not already contained in the input, so [c-f]
|
| + // will be skipped but [C-F] will be added. If this range is not
|
| + // completely contained in a block we do this for all the blocks
|
| + // covered by the range (handling characters that is not in a block
|
| + // as a "singleton block").
|
| + unibrow::uchar range[unibrow::Ecma262UnCanonicalize::kMaxWidth];
|
| + int pos = bottom;
|
| + while (pos <= top) {
|
| + int length = isolate->jsregexp_canonrange()->get(pos, '\0', range);
|
| + uc16 block_end;
|
| + if (length == 0) {
|
| + block_end = pos;
|
| + } else {
|
| + DCHECK_EQ(1, length);
|
| + block_end = range[0];
|
| + }
|
| + int end = (block_end > top) ? top : block_end;
|
| + length = isolate->jsregexp_uncanonicalize()->get(block_end, '\0', range);
|
| + for (int i = 0; i < length; i++) {
|
| + uc32 c = range[i];
|
| + uc16 range_from = c - (block_end - pos);
|
| + uc16 range_to = c - (block_end - end);
|
| + if (!(bottom <= range_from && range_to <= top)) {
|
| + ranges->Add(CharacterRange(range_from, range_to), zone);
|
| + }
|
| + }
|
| + pos = end + 1;
|
| + }
|
| + }
|
| +}
|
| +
|
| +
|
| +bool CharacterRange::IsCanonical(ZoneList<CharacterRange>* ranges) {
|
| + DCHECK_NOT_NULL(ranges);
|
| + int n = ranges->length();
|
| + if (n <= 1) return true;
|
| + int max = ranges->at(0).to();
|
| + for (int i = 1; i < n; i++) {
|
| + CharacterRange next_range = ranges->at(i);
|
| + if (next_range.from() <= max + 1) return false;
|
| + max = next_range.to();
|
| + }
|
| + return true;
|
| +}
|
| +
|
| +
|
| +ZoneList<CharacterRange>* CharacterSet::ranges(Zone* zone) {
|
| + if (ranges_ == NULL) {
|
| + ranges_ = new(zone) ZoneList<CharacterRange>(2, zone);
|
| + CharacterRange::AddClassEscape(standard_set_type_, ranges_, zone);
|
| + }
|
| + return ranges_;
|
| +}
|
| +
|
| +
|
| +// Move a number of elements in a zonelist to another position
|
| +// in the same list. Handles overlapping source and target areas.
|
| +static void MoveRanges(ZoneList<CharacterRange>* list,
|
| + int from,
|
| + int to,
|
| + int count) {
|
| + // Ranges are potentially overlapping.
|
| + if (from < to) {
|
| + for (int i = count - 1; i >= 0; i--) {
|
| + list->at(to + i) = list->at(from + i);
|
| + }
|
| + } else {
|
| + for (int i = 0; i < count; i++) {
|
| + list->at(to + i) = list->at(from + i);
|
| + }
|
| + }
|
| +}
|
| +
|
| +
|
| +static int InsertRangeInCanonicalList(ZoneList<CharacterRange>* list,
|
| + int count,
|
| + CharacterRange insert) {
|
| + // Inserts a range into list[0..count[, which must be sorted
|
| + // by from value and non-overlapping and non-adjacent, using at most
|
| + // list[0..count] for the result. Returns the number of resulting
|
| + // canonicalized ranges. Inserting a range may collapse existing ranges into
|
| + // fewer ranges, so the return value can be anything in the range 1..count+1.
|
| + uc16 from = insert.from();
|
| + uc16 to = insert.to();
|
| + int start_pos = 0;
|
| + int end_pos = count;
|
| + for (int i = count - 1; i >= 0; i--) {
|
| + CharacterRange current = list->at(i);
|
| + if (current.from() > to + 1) {
|
| + end_pos = i;
|
| + } else if (current.to() + 1 < from) {
|
| + start_pos = i + 1;
|
| + break;
|
| + }
|
| + }
|
| +
|
| + // Inserted range overlaps, or is adjacent to, ranges at positions
|
| + // [start_pos..end_pos[. Ranges before start_pos or at or after end_pos are
|
| + // not affected by the insertion.
|
| + // If start_pos == end_pos, the range must be inserted before start_pos.
|
| + // if start_pos < end_pos, the entire range from start_pos to end_pos
|
| + // must be merged with the insert range.
|
| +
|
| + if (start_pos == end_pos) {
|
| + // Insert between existing ranges at position start_pos.
|
| + if (start_pos < count) {
|
| + MoveRanges(list, start_pos, start_pos + 1, count - start_pos);
|
| + }
|
| + list->at(start_pos) = insert;
|
| + return count + 1;
|
| + }
|
| + if (start_pos + 1 == end_pos) {
|
| + // Replace single existing range at position start_pos.
|
| + CharacterRange to_replace = list->at(start_pos);
|
| + int new_from = Min(to_replace.from(), from);
|
| + int new_to = Max(to_replace.to(), to);
|
| + list->at(start_pos) = CharacterRange(new_from, new_to);
|
| + return count;
|
| + }
|
| + // Replace a number of existing ranges from start_pos to end_pos - 1.
|
| + // Move the remaining ranges down.
|
| +
|
| + int new_from = Min(list->at(start_pos).from(), from);
|
| + int new_to = Max(list->at(end_pos - 1).to(), to);
|
| + if (end_pos < count) {
|
| + MoveRanges(list, end_pos, start_pos + 1, count - end_pos);
|
| + }
|
| + list->at(start_pos) = CharacterRange(new_from, new_to);
|
| + return count - (end_pos - start_pos) + 1;
|
| +}
|
| +
|
| +
|
| +void CharacterSet::Canonicalize() {
|
| + // Special/default classes are always considered canonical. The result
|
| + // of calling ranges() will be sorted.
|
| + if (ranges_ == NULL) return;
|
| + CharacterRange::Canonicalize(ranges_);
|
| +}
|
| +
|
| +
|
| +void CharacterRange::Canonicalize(ZoneList<CharacterRange>* character_ranges) {
|
| + if (character_ranges->length() <= 1) return;
|
| + // Check whether ranges are already canonical (increasing, non-overlapping,
|
| + // non-adjacent).
|
| + int n = character_ranges->length();
|
| + int max = character_ranges->at(0).to();
|
| + int i = 1;
|
| + while (i < n) {
|
| + CharacterRange current = character_ranges->at(i);
|
| + if (current.from() <= max + 1) {
|
| + break;
|
| + }
|
| + max = current.to();
|
| + i++;
|
| + }
|
| + // Canonical until the i'th range. If that's all of them, we are done.
|
| + if (i == n) return;
|
| +
|
| + // The ranges at index i and forward are not canonicalized. Make them so by
|
| + // doing the equivalent of insertion sort (inserting each into the previous
|
| + // list, in order).
|
| + // Notice that inserting a range can reduce the number of ranges in the
|
| + // result due to combining of adjacent and overlapping ranges.
|
| + int read = i; // Range to insert.
|
| + int num_canonical = i; // Length of canonicalized part of list.
|
| + do {
|
| + num_canonical = InsertRangeInCanonicalList(character_ranges,
|
| + num_canonical,
|
| + character_ranges->at(read));
|
| + read++;
|
| + } while (read < n);
|
| + character_ranges->Rewind(num_canonical);
|
| +
|
| + DCHECK(CharacterRange::IsCanonical(character_ranges));
|
| +}
|
| +
|
| +
|
| +void CharacterRange::Negate(ZoneList<CharacterRange>* ranges,
|
| + ZoneList<CharacterRange>* negated_ranges,
|
| + Zone* zone) {
|
| + DCHECK(CharacterRange::IsCanonical(ranges));
|
| + DCHECK_EQ(0, negated_ranges->length());
|
| + int range_count = ranges->length();
|
| + uc16 from = 0;
|
| + int i = 0;
|
| + if (range_count > 0 && ranges->at(0).from() == 0) {
|
| + from = ranges->at(0).to();
|
| + i = 1;
|
| + }
|
| + while (i < range_count) {
|
| + CharacterRange range = ranges->at(i);
|
| + negated_ranges->Add(CharacterRange(from + 1, range.from() - 1), zone);
|
| + from = range.to();
|
| + i++;
|
| + }
|
| + if (from < String::kMaxUtf16CodeUnit) {
|
| + negated_ranges->Add(CharacterRange(from + 1, String::kMaxUtf16CodeUnit),
|
| + zone);
|
| + }
|
| +}
|
| +
|
| +
|
| +// -------------------------------------------------------------------
|
| +// Splay tree
|
| +
|
| +
|
| +OutSet* OutSet::Extend(unsigned value, Zone* zone) {
|
| + if (Get(value))
|
| + return this;
|
| + if (successors(zone) != NULL) {
|
| + for (int i = 0; i < successors(zone)->length(); i++) {
|
| + OutSet* successor = successors(zone)->at(i);
|
| + if (successor->Get(value))
|
| + return successor;
|
| + }
|
| + } else {
|
| + successors_ = new(zone) ZoneList<OutSet*>(2, zone);
|
| + }
|
| + OutSet* result = new(zone) OutSet(first_, remaining_);
|
| + result->Set(value, zone);
|
| + successors(zone)->Add(result, zone);
|
| + return result;
|
| +}
|
| +
|
| +
|
| +void OutSet::Set(unsigned value, Zone *zone) {
|
| + if (value < kFirstLimit) {
|
| + first_ |= (1 << value);
|
| + } else {
|
| + if (remaining_ == NULL)
|
| + remaining_ = new(zone) ZoneList<unsigned>(1, zone);
|
| + if (remaining_->is_empty() || !remaining_->Contains(value))
|
| + remaining_->Add(value, zone);
|
| + }
|
| +}
|
| +
|
| +
|
| +bool OutSet::Get(unsigned value) const {
|
| + if (value < kFirstLimit) {
|
| + return (first_ & (1 << value)) != 0;
|
| + } else if (remaining_ == NULL) {
|
| + return false;
|
| + } else {
|
| + return remaining_->Contains(value);
|
| + }
|
| +}
|
| +
|
| +
|
| +const uc16 DispatchTable::Config::kNoKey = unibrow::Utf8::kBadChar;
|
| +
|
| +
|
| +void DispatchTable::AddRange(CharacterRange full_range, int value,
|
| + Zone* zone) {
|
| + CharacterRange current = full_range;
|
| + if (tree()->is_empty()) {
|
| + // If this is the first range we just insert into the table.
|
| + ZoneSplayTree<Config>::Locator loc;
|
| + DCHECK_RESULT(tree()->Insert(current.from(), &loc));
|
| + loc.set_value(Entry(current.from(), current.to(),
|
| + empty()->Extend(value, zone)));
|
| + return;
|
| + }
|
| + // First see if there is a range to the left of this one that
|
| + // overlaps.
|
| + ZoneSplayTree<Config>::Locator loc;
|
| + if (tree()->FindGreatestLessThan(current.from(), &loc)) {
|
| + Entry* entry = &loc.value();
|
| + // If we've found a range that overlaps with this one, and it
|
| + // starts strictly to the left of this one, we have to fix it
|
| + // because the following code only handles ranges that start on
|
| + // or after the start point of the range we're adding.
|
| + if (entry->from() < current.from() && entry->to() >= current.from()) {
|
| + // Snap the overlapping range in half around the start point of
|
| + // the range we're adding.
|
| + CharacterRange left(entry->from(), current.from() - 1);
|
| + CharacterRange right(current.from(), entry->to());
|
| + // The left part of the overlapping range doesn't overlap.
|
| + // Truncate the whole entry to be just the left part.
|
| + entry->set_to(left.to());
|
| + // The right part is the one that overlaps. We add this part
|
| + // to the map and let the next step deal with merging it with
|
| + // the range we're adding.
|
| + ZoneSplayTree<Config>::Locator loc;
|
| + DCHECK_RESULT(tree()->Insert(right.from(), &loc));
|
| + loc.set_value(Entry(right.from(),
|
| + right.to(),
|
| + entry->out_set()));
|
| + }
|
| + }
|
| + while (current.is_valid()) {
|
| + if (tree()->FindLeastGreaterThan(current.from(), &loc) &&
|
| + (loc.value().from() <= current.to()) &&
|
| + (loc.value().to() >= current.from())) {
|
| + Entry* entry = &loc.value();
|
| + // We have overlap. If there is space between the start point of
|
| + // the range we're adding and where the overlapping range starts
|
| + // then we have to add a range covering just that space.
|
| + if (current.from() < entry->from()) {
|
| + ZoneSplayTree<Config>::Locator ins;
|
| + DCHECK_RESULT(tree()->Insert(current.from(), &ins));
|
| + ins.set_value(Entry(current.from(),
|
| + entry->from() - 1,
|
| + empty()->Extend(value, zone)));
|
| + current.set_from(entry->from());
|
| + }
|
| + DCHECK_EQ(current.from(), entry->from());
|
| + // If the overlapping range extends beyond the one we want to add
|
| + // we have to snap the right part off and add it separately.
|
| + if (entry->to() > current.to()) {
|
| + ZoneSplayTree<Config>::Locator ins;
|
| + DCHECK_RESULT(tree()->Insert(current.to() + 1, &ins));
|
| + ins.set_value(Entry(current.to() + 1,
|
| + entry->to(),
|
| + entry->out_set()));
|
| + entry->set_to(current.to());
|
| + }
|
| + DCHECK(entry->to() <= current.to());
|
| + // The overlapping range is now completely contained by the range
|
| + // we're adding so we can just update it and move the start point
|
| + // of the range we're adding just past it.
|
| + entry->AddValue(value, zone);
|
| + // Bail out if the last interval ended at 0xFFFF since otherwise
|
| + // adding 1 will wrap around to 0.
|
| + if (entry->to() == String::kMaxUtf16CodeUnit)
|
| + break;
|
| + DCHECK(entry->to() + 1 > current.from());
|
| + current.set_from(entry->to() + 1);
|
| + } else {
|
| + // There is no overlap so we can just add the range
|
| + ZoneSplayTree<Config>::Locator ins;
|
| + DCHECK_RESULT(tree()->Insert(current.from(), &ins));
|
| + ins.set_value(Entry(current.from(),
|
| + current.to(),
|
| + empty()->Extend(value, zone)));
|
| + break;
|
| + }
|
| + }
|
| +}
|
| +
|
| +
|
| +OutSet* DispatchTable::Get(uc16 value) {
|
| + ZoneSplayTree<Config>::Locator loc;
|
| + if (!tree()->FindGreatestLessThan(value, &loc))
|
| + return empty();
|
| + Entry* entry = &loc.value();
|
| + if (value <= entry->to())
|
| + return entry->out_set();
|
| + else
|
| + return empty();
|
| +}
|
| +
|
| +
|
| +// -------------------------------------------------------------------
|
| +// Analysis
|
| +
|
| +
|
| +void Analysis::EnsureAnalyzed(RegExpNode* that) {
|
| + StackLimitCheck check(that->zone()->isolate());
|
| + if (check.HasOverflowed()) {
|
| + fail("Stack overflow");
|
| + return;
|
| + }
|
| + if (that->info()->been_analyzed || that->info()->being_analyzed)
|
| + return;
|
| + that->info()->being_analyzed = true;
|
| + that->Accept(this);
|
| + that->info()->being_analyzed = false;
|
| + that->info()->been_analyzed = true;
|
| +}
|
| +
|
| +
|
| +void Analysis::VisitEnd(EndNode* that) {
|
| + // nothing to do
|
| +}
|
| +
|
| +
|
| +void TextNode::CalculateOffsets() {
|
| + int element_count = elements()->length();
|
| + // Set up the offsets of the elements relative to the start. This is a fixed
|
| + // quantity since a TextNode can only contain fixed-width things.
|
| + int cp_offset = 0;
|
| + for (int i = 0; i < element_count; i++) {
|
| + TextElement& elm = elements()->at(i);
|
| + elm.set_cp_offset(cp_offset);
|
| + cp_offset += elm.length();
|
| + }
|
| +}
|
| +
|
| +
|
| +void Analysis::VisitText(TextNode* that) {
|
| + if (ignore_case_) {
|
| + that->MakeCaseIndependent(is_one_byte_);
|
| + }
|
| + EnsureAnalyzed(that->on_success());
|
| + if (!has_failed()) {
|
| + that->CalculateOffsets();
|
| + }
|
| +}
|
| +
|
| +
|
| +void Analysis::VisitAction(ActionNode* that) {
|
| + RegExpNode* target = that->on_success();
|
| + EnsureAnalyzed(target);
|
| + if (!has_failed()) {
|
| + // If the next node is interested in what it follows then this node
|
| + // has to be interested too so it can pass the information on.
|
| + that->info()->AddFromFollowing(target->info());
|
| + }
|
| +}
|
| +
|
| +
|
| +void Analysis::VisitChoice(ChoiceNode* that) {
|
| + NodeInfo* info = that->info();
|
| + for (int i = 0; i < that->alternatives()->length(); i++) {
|
| + RegExpNode* node = that->alternatives()->at(i).node();
|
| + EnsureAnalyzed(node);
|
| + if (has_failed()) return;
|
| + // Anything the following nodes need to know has to be known by
|
| + // this node also, so it can pass it on.
|
| + info->AddFromFollowing(node->info());
|
| + }
|
| +}
|
| +
|
| +
|
| +void Analysis::VisitLoopChoice(LoopChoiceNode* that) {
|
| + NodeInfo* info = that->info();
|
| + for (int i = 0; i < that->alternatives()->length(); i++) {
|
| + RegExpNode* node = that->alternatives()->at(i).node();
|
| + if (node != that->loop_node()) {
|
| + EnsureAnalyzed(node);
|
| + if (has_failed()) return;
|
| + info->AddFromFollowing(node->info());
|
| + }
|
| + }
|
| + // Check the loop last since it may need the value of this node
|
| + // to get a correct result.
|
| + EnsureAnalyzed(that->loop_node());
|
| + if (!has_failed()) {
|
| + info->AddFromFollowing(that->loop_node()->info());
|
| + }
|
| +}
|
| +
|
| +
|
| +void Analysis::VisitBackReference(BackReferenceNode* that) {
|
| + EnsureAnalyzed(that->on_success());
|
| +}
|
| +
|
| +
|
| +void Analysis::VisitAssertion(AssertionNode* that) {
|
| + EnsureAnalyzed(that->on_success());
|
| +}
|
| +
|
| +
|
| +void BackReferenceNode::FillInBMInfo(int offset,
|
| + int budget,
|
| + BoyerMooreLookahead* bm,
|
| + bool not_at_start) {
|
| + // Working out the set of characters that a backreference can match is too
|
| + // hard, so we just say that any character can match.
|
| + bm->SetRest(offset);
|
| + SaveBMInfo(bm, not_at_start, offset);
|
| +}
|
| +
|
| +
|
| +STATIC_ASSERT(BoyerMoorePositionInfo::kMapSize ==
|
| + RegExpMacroAssembler::kTableSize);
|
| +
|
| +
|
| +void ChoiceNode::FillInBMInfo(int offset,
|
| + int budget,
|
| + BoyerMooreLookahead* bm,
|
| + bool not_at_start) {
|
| + ZoneList<GuardedAlternative>* alts = alternatives();
|
| + budget = (budget - 1) / alts->length();
|
| + for (int i = 0; i < alts->length(); i++) {
|
| + GuardedAlternative& alt = alts->at(i);
|
| + if (alt.guards() != NULL && alt.guards()->length() != 0) {
|
| + bm->SetRest(offset); // Give up trying to fill in info.
|
| + SaveBMInfo(bm, not_at_start, offset);
|
| + return;
|
| + }
|
| + alt.node()->FillInBMInfo(offset, budget, bm, not_at_start);
|
| + }
|
| + SaveBMInfo(bm, not_at_start, offset);
|
| +}
|
| +
|
| +
|
| +void TextNode::FillInBMInfo(int initial_offset,
|
| + int budget,
|
| + BoyerMooreLookahead* bm,
|
| + bool not_at_start) {
|
| + if (initial_offset >= bm->length()) return;
|
| + int offset = initial_offset;
|
| + int max_char = bm->max_char();
|
| + for (int i = 0; i < elements()->length(); i++) {
|
| + if (offset >= bm->length()) {
|
| + if (initial_offset == 0) set_bm_info(not_at_start, bm);
|
| + return;
|
| + }
|
| + TextElement text = elements()->at(i);
|
| + if (text.text_type() == TextElement::ATOM) {
|
| + RegExpAtom* atom = text.atom();
|
| + for (int j = 0; j < atom->length(); j++, offset++) {
|
| + if (offset >= bm->length()) {
|
| + if (initial_offset == 0) set_bm_info(not_at_start, bm);
|
| + return;
|
| + }
|
| + uc16 character = atom->data()[j];
|
| + if (bm->compiler()->ignore_case()) {
|
| + unibrow::uchar chars[unibrow::Ecma262UnCanonicalize::kMaxWidth];
|
| + int length = GetCaseIndependentLetters(
|
| + Isolate::Current(),
|
| + character,
|
| + bm->max_char() == String::kMaxOneByteCharCode,
|
| + chars);
|
| + for (int j = 0; j < length; j++) {
|
| + bm->Set(offset, chars[j]);
|
| + }
|
| + } else {
|
| + if (character <= max_char) bm->Set(offset, character);
|
| + }
|
| + }
|
| + } else {
|
| + DCHECK_EQ(TextElement::CHAR_CLASS, text.text_type());
|
| + RegExpCharacterClass* char_class = text.char_class();
|
| + ZoneList<CharacterRange>* ranges = char_class->ranges(zone());
|
| + if (char_class->is_negated()) {
|
| + bm->SetAll(offset);
|
| + } else {
|
| + for (int k = 0; k < ranges->length(); k++) {
|
| + CharacterRange& range = ranges->at(k);
|
| + if (range.from() > max_char) continue;
|
| + int to = Min(max_char, static_cast<int>(range.to()));
|
| + bm->SetInterval(offset, Interval(range.from(), to));
|
| + }
|
| + }
|
| + offset++;
|
| + }
|
| + }
|
| + if (offset >= bm->length()) {
|
| + if (initial_offset == 0) set_bm_info(not_at_start, bm);
|
| + return;
|
| + }
|
| + on_success()->FillInBMInfo(offset,
|
| + budget - 1,
|
| + bm,
|
| + true); // Not at start after a text node.
|
| + 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) {
|
| + CharacterRange range(from, entry.to());
|
| + constructor_->AddRange(range);
|
| +}
|
| +
|
| +
|
| +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(last, range.from() - 1));
|
| + if (range.to() >= last) {
|
| + if (range.to() == String::kMaxUtf16CodeUnit) {
|
| + return;
|
| + } else {
|
| + last = range.to() + 1;
|
| + }
|
| + }
|
| + }
|
| + AddRange(CharacterRange(last, String::kMaxUtf16CodeUnit));
|
| +}
|
| +
|
| +
|
| +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(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);
|
| +}
|
| +
|
| +
|
| +RegExpEngine::CompilationResult RegExpEngine::Compile(
|
| + RegExpCompileData* data, bool ignore_case, bool is_global,
|
| + bool is_multiline, bool is_sticky, Handle<String> pattern,
|
| + Handle<String> sample_subject, bool is_one_byte, Zone* zone) {
|
| + if ((data->capture_count + 1) * 2 - 1 > RegExpMacroAssembler::kMaxRegister) {
|
| + return IrregexpRegExpTooBig(zone->isolate());
|
| + }
|
| + RegExpCompiler compiler(data->capture_count, ignore_case, is_one_byte, zone);
|
| +
|
| + // Sample some characters from the middle of the string.
|
| + static const int kSampleSize = 128;
|
| +
|
| + sample_subject = String::Flatten(sample_subject);
|
| + int chars_sampled = 0;
|
| + int half_way = (sample_subject->length() - kSampleSize) / 2;
|
| + for (int i = Max(0, half_way);
|
| + i < sample_subject->length() && chars_sampled < kSampleSize;
|
| + i++, chars_sampled++) {
|
| + compiler.frequency_collator()->CountCharacter(sample_subject->Get(i));
|
| + }
|
| +
|
| + // Wrap the body of the regexp in capture #0.
|
| + RegExpNode* captured_body = RegExpCapture::ToNode(data->tree,
|
| + 0,
|
| + &compiler,
|
| + compiler.accept());
|
| + RegExpNode* node = captured_body;
|
| + bool is_end_anchored = data->tree->IsAnchoredAtEnd();
|
| + bool is_start_anchored = data->tree->IsAnchoredAtStart();
|
| + int max_length = data->tree->max_match();
|
| + if (!is_start_anchored && !is_sticky) {
|
| + // Add a .*? at the beginning, outside the body capture, unless
|
| + // this expression is anchored at the beginning or sticky.
|
| + RegExpNode* loop_node =
|
| + RegExpQuantifier::ToNode(0,
|
| + RegExpTree::kInfinity,
|
| + false,
|
| + new(zone) RegExpCharacterClass('*'),
|
| + &compiler,
|
| + captured_body,
|
| + data->contains_anchor);
|
| +
|
| + if (data->contains_anchor) {
|
| + // Unroll loop once, to take care of the case that might start
|
| + // at the start of input.
|
| + ChoiceNode* first_step_node = new(zone) ChoiceNode(2, zone);
|
| + first_step_node->AddAlternative(GuardedAlternative(captured_body));
|
| + first_step_node->AddAlternative(GuardedAlternative(
|
| + new(zone) TextNode(new(zone) RegExpCharacterClass('*'), loop_node)));
|
| + node = first_step_node;
|
| + } else {
|
| + node = loop_node;
|
| + }
|
| + }
|
| + if (is_one_byte) {
|
| + node = node->FilterOneByte(RegExpCompiler::kMaxRecursion, ignore_case);
|
| + // Do it again to propagate the new nodes to places where they were not
|
| + // put because they had not been calculated yet.
|
| + if (node != NULL) {
|
| + node = node->FilterOneByte(RegExpCompiler::kMaxRecursion, ignore_case);
|
| + }
|
| + }
|
| +
|
| + if (node == NULL) node = new(zone) EndNode(EndNode::BACKTRACK, zone);
|
| + data->node = node;
|
| + Analysis analysis(ignore_case, is_one_byte);
|
| + analysis.EnsureAnalyzed(node);
|
| + if (analysis.has_failed()) {
|
| + const char* error_message = analysis.error_message();
|
| + return CompilationResult(zone->isolate(), error_message);
|
| + }
|
| +
|
| + // Create the correct assembler for the architecture.
|
| +#ifndef V8_INTERPRETED_REGEXP
|
| + // Native regexp implementation.
|
| +
|
| + NativeRegExpMacroAssembler::Mode mode =
|
| + is_one_byte ? NativeRegExpMacroAssembler::LATIN1
|
| + : NativeRegExpMacroAssembler::UC16;
|
| +
|
| +#if V8_TARGET_ARCH_IA32
|
| + RegExpMacroAssemblerIA32 macro_assembler(mode, (data->capture_count + 1) * 2,
|
| + zone);
|
| +#elif V8_TARGET_ARCH_X64
|
| + RegExpMacroAssemblerX64 macro_assembler(mode, (data->capture_count + 1) * 2,
|
| + zone);
|
| +#elif V8_TARGET_ARCH_ARM
|
| + RegExpMacroAssemblerARM macro_assembler(mode, (data->capture_count + 1) * 2,
|
| + zone);
|
| +#elif V8_TARGET_ARCH_ARM64
|
| + RegExpMacroAssemblerARM64 macro_assembler(mode, (data->capture_count + 1) * 2,
|
| + zone);
|
| +#elif V8_TARGET_ARCH_MIPS
|
| + RegExpMacroAssemblerMIPS macro_assembler(mode, (data->capture_count + 1) * 2,
|
| + zone);
|
| +#elif V8_TARGET_ARCH_MIPS64
|
| + RegExpMacroAssemblerMIPS macro_assembler(mode, (data->capture_count + 1) * 2,
|
| + zone);
|
| +#elif V8_TARGET_ARCH_X87
|
| + RegExpMacroAssemblerX87 macro_assembler(mode, (data->capture_count + 1) * 2,
|
| + zone);
|
| +#else
|
| +#error "Unsupported architecture"
|
| +#endif
|
| +
|
| +#else // V8_INTERPRETED_REGEXP
|
| + // Interpreted regexp implementation.
|
| + EmbeddedVector<byte, 1024> codes;
|
| + RegExpMacroAssemblerIrregexp macro_assembler(codes, zone);
|
| +#endif // V8_INTERPRETED_REGEXP
|
| +
|
| + // Inserted here, instead of in Assembler, because it depends on information
|
| + // in the AST that isn't replicated in the Node structure.
|
| + static const int kMaxBacksearchLimit = 1024;
|
| + if (is_end_anchored &&
|
| + !is_start_anchored &&
|
| + max_length < kMaxBacksearchLimit) {
|
| + macro_assembler.SetCurrentPositionFromEnd(max_length);
|
| + }
|
| +
|
| + if (is_global) {
|
| + macro_assembler.set_global_mode(
|
| + (data->tree->min_match() > 0)
|
| + ? RegExpMacroAssembler::GLOBAL_NO_ZERO_LENGTH_CHECK
|
| + : RegExpMacroAssembler::GLOBAL);
|
| + }
|
| +
|
| + return compiler.Assemble(¯o_assembler,
|
| + node,
|
| + data->capture_count,
|
| + pattern);
|
| +}
|
| +
|
| +} // namespace dart
|
|
|
Chromium Code Reviews
Issue 678193004:
Copy irregexp related code from V8. (Closed)
Base URL: https://dart.googlecode.com/svn/branches/bleeding_edge/dart