| // 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" |
| |
| #include <memory> |
| |
| #include "platform/splay-tree-inl.h" |
| #include "platform/unicode.h" |
| |
| #include "unicode/uniset.h" |
| |
| #include "vm/dart_entry.h" |
| #include "vm/regexp_assembler.h" |
| #include "vm/regexp_assembler_bytecode.h" |
| #include "vm/regexp_ast.h" |
| #include "vm/symbols.h" |
| #include "vm/thread.h" |
| #include "vm/unibrow-inl.h" |
| |
| #if !defined(DART_PRECOMPILED_RUNTIME) |
| #include "vm/regexp_assembler_ir.h" |
| #endif // !defined(DART_PRECOMPILED_RUNTIME) |
| |
| #define Z (zone()) |
| |
| namespace dart { |
| |
| // Default to generating optimized regexp code. |
| static const bool kRegexpOptimization = true; |
| |
| // More makes code generation slower, less makes V8 benchmark score lower. |
| static const intptr_t kMaxLookaheadForBoyerMoore = 8; |
| |
| ContainedInLattice AddRange(ContainedInLattice containment, |
| const int32_t* ranges, |
| intptr_t ranges_length, |
| Interval new_range) { |
| ASSERT((ranges_length & 1) == 1); |
| ASSERT(ranges[ranges_length - 1] == Utf::kMaxCodePoint + 1); |
| if (containment == kLatticeUnknown) return containment; |
| bool inside = false; |
| int32_t last = 0; |
| for (intptr_t i = 0; i < ranges_length; |
| inside = !inside, last = ranges[i], i++) { |
| // Consider the range from last to ranges[i]. |
| // We haven't got to the new range yet. |
| if (ranges[i] <= new_range.from()) continue; |
| // New range is wholly inside last-ranges[i]. Note that new_range.to() is |
| // inclusive, but the values in ranges are not. |
| if (last <= new_range.from() && new_range.to() < ranges[i]) { |
| return Combine(containment, inside ? kLatticeIn : kLatticeOut); |
| } |
| return kLatticeUnknown; |
| } |
| return containment; |
| } |
| |
| // ------------------------------------------------------------------- |
| // 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 |
| // IR code that is subsequently compiled to native code. |
| |
| // The Irregexp regexp engine is structured in three steps. |
| // 1) The parser generates an abstract syntax tree. See regexp_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 IR instructions 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 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) { |
| UNREACHABLE(); |
| } |
| |
| void RegExpAtom::AppendToText(RegExpText* text) { |
| text->AddElement(TextElement::Atom(this)); |
| } |
| |
| void RegExpCharacterClass::AppendToText(RegExpText* text) { |
| text->AddElement(TextElement::CharClass(this)); |
| } |
| |
| void RegExpText::AppendToText(RegExpText* text) { |
| for (intptr_t i = 0; i < elements()->length(); i++) |
| text->AddElement((*elements())[i]); |
| } |
| |
| TextElement TextElement::Atom(RegExpAtom* atom) { |
| return TextElement(ATOM, atom); |
| } |
| |
| TextElement TextElement::CharClass(RegExpCharacterClass* char_class) { |
| return TextElement(CHAR_CLASS, char_class); |
| } |
| |
| intptr_t TextElement::length() const { |
| switch (text_type()) { |
| case ATOM: |
| return atom()->length(); |
| |
| case CHAR_CLASS: |
| return 1; |
| } |
| UNREACHABLE(); |
| return 0; |
| } |
| |
| class FrequencyCollator : public ValueObject { |
| public: |
| FrequencyCollator() : total_samples_(0) { |
| for (intptr_t i = 0; i < RegExpMacroAssembler::kTableSize; i++) { |
| frequencies_[i] = CharacterFrequency(i); |
| } |
| } |
| |
| void CountCharacter(intptr_t character) { |
| intptr_t 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). |
| intptr_t Frequency(intptr_t in_character) { |
| ASSERT((in_character & RegExpMacroAssembler::kTableMask) == in_character); |
| if (total_samples_ < 1) return 1; // Division by zero. |
| intptr_t 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(intptr_t character) |
| : counter_(0), character_(character) {} |
| |
| void Increment() { counter_++; } |
| intptr_t counter() { return counter_; } |
| intptr_t character() { return character_; } |
| |
| private: |
| intptr_t counter_; |
| intptr_t character_; |
| |
| DISALLOW_ALLOCATION(); |
| }; |
| |
| private: |
| CharacterFrequency frequencies_[RegExpMacroAssembler::kTableSize]; |
| intptr_t total_samples_; |
| }; |
| |
| class RegExpCompiler : public ValueObject { |
| public: |
| RegExpCompiler(intptr_t capture_count, bool is_one_byte); |
| |
| intptr_t AllocateRegister() { return next_register_++; } |
| |
| // Lookarounds to match lone surrogates for unicode character class matches |
| // are never nested. We can therefore reuse registers. |
| intptr_t UnicodeLookaroundStackRegister() { |
| if (unicode_lookaround_stack_register_ == kNoRegister) { |
| unicode_lookaround_stack_register_ = AllocateRegister(); |
| } |
| return unicode_lookaround_stack_register_; |
| } |
| |
| intptr_t UnicodeLookaroundPositionRegister() { |
| if (unicode_lookaround_position_register_ == kNoRegister) { |
| unicode_lookaround_position_register_ = AllocateRegister(); |
| } |
| return unicode_lookaround_position_register_; |
| } |
| |
| #if !defined(DART_PRECOMPILED_RUNTIME) |
| RegExpEngine::CompilationResult Assemble(IRRegExpMacroAssembler* assembler, |
| RegExpNode* start, |
| intptr_t capture_count, |
| const String& pattern); |
| #endif |
| |
| RegExpEngine::CompilationResult Assemble( |
| BytecodeRegExpMacroAssembler* assembler, |
| RegExpNode* start, |
| intptr_t capture_count, |
| const String& pattern); |
| |
| inline void AddWork(RegExpNode* node) { work_list_->Add(node); } |
| |
| static const intptr_t kImplementationOffset = 0; |
| static const intptr_t kNumberOfRegistersOffset = 0; |
| static const intptr_t kCodeOffset = 1; |
| |
| RegExpMacroAssembler* macro_assembler() { return macro_assembler_; } |
| EndNode* accept() { return accept_; } |
| |
| static const intptr_t kMaxRecursion = 100; |
| inline intptr_t recursion_depth() { return recursion_depth_; } |
| inline void IncrementRecursionDepth() { recursion_depth_++; } |
| inline void DecrementRecursionDepth() { recursion_depth_--; } |
| |
| void SetRegExpTooBig() { reg_exp_too_big_ = true; } |
| |
| inline bool one_byte() const { return is_one_byte_; } |
| bool read_backward() { return read_backward_; } |
| void set_read_backward(bool value) { read_backward_ = value; } |
| FrequencyCollator* frequency_collator() { return &frequency_collator_; } |
| |
| intptr_t current_expansion_factor() { return current_expansion_factor_; } |
| void set_current_expansion_factor(intptr_t value) { |
| current_expansion_factor_ = value; |
| } |
| |
| Zone* zone() const { return zone_; } |
| |
| static const intptr_t kNoRegister = -1; |
| |
| private: |
| EndNode* accept_; |
| intptr_t next_register_; |
| intptr_t unicode_lookaround_stack_register_; |
| intptr_t unicode_lookaround_position_register_; |
| ZoneGrowableArray<RegExpNode*>* work_list_; |
| intptr_t recursion_depth_; |
| RegExpMacroAssembler* macro_assembler_; |
| bool is_one_byte_; |
| bool reg_exp_too_big_; |
| bool read_backward_; |
| intptr_t current_expansion_factor_; |
| FrequencyCollator frequency_collator_; |
| Zone* zone_; |
| }; |
| |
| class RecursionCheck : public ValueObject { |
| public: |
| explicit RecursionCheck(RegExpCompiler* compiler) : compiler_(compiler) { |
| compiler->IncrementRecursionDepth(); |
| } |
| ~RecursionCheck() { compiler_->DecrementRecursionDepth(); } |
| |
| private: |
| RegExpCompiler* compiler_; |
| }; |
| |
| static RegExpEngine::CompilationResult IrregexpRegExpTooBig() { |
| return RegExpEngine::CompilationResult("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(intptr_t capture_count, bool is_one_byte) |
| : next_register_(2 * (capture_count + 1)), |
| unicode_lookaround_stack_register_(kNoRegister), |
| unicode_lookaround_position_register_(kNoRegister), |
| work_list_(NULL), |
| recursion_depth_(0), |
| is_one_byte_(is_one_byte), |
| reg_exp_too_big_(false), |
| read_backward_(false), |
| current_expansion_factor_(1), |
| zone_(Thread::Current()->zone()) { |
| accept_ = new (Z) EndNode(EndNode::ACCEPT, Z); |
| } |
| |
| #if !defined(DART_PRECOMPILED_RUNTIME) |
| RegExpEngine::CompilationResult RegExpCompiler::Assemble( |
| IRRegExpMacroAssembler* macro_assembler, |
| RegExpNode* start, |
| intptr_t capture_count, |
| const String& pattern) { |
| macro_assembler->set_slow_safe(false /* use_slow_safe_regexp_compiler */); |
| macro_assembler_ = macro_assembler; |
| |
| ZoneGrowableArray<RegExpNode*> work_list(0); |
| work_list_ = &work_list; |
| BlockLabel fail; |
| macro_assembler_->PushBacktrack(&fail); |
| Trace new_trace; |
| start->Emit(this, &new_trace); |
| macro_assembler_->BindBlock(&fail); |
| macro_assembler_->Fail(); |
| while (!work_list.is_empty()) { |
| work_list.RemoveLast()->Emit(this, &new_trace); |
| } |
| if (reg_exp_too_big_) return IrregexpRegExpTooBig(); |
| |
| macro_assembler->GenerateBacktrackBlock(); |
| macro_assembler->FinalizeRegistersArray(); |
| |
| return RegExpEngine::CompilationResult( |
| macro_assembler->backtrack_goto(), macro_assembler->graph_entry(), |
| macro_assembler->num_blocks(), macro_assembler->num_stack_locals(), |
| next_register_); |
| } |
| #endif |
| |
| RegExpEngine::CompilationResult RegExpCompiler::Assemble( |
| BytecodeRegExpMacroAssembler* macro_assembler, |
| RegExpNode* start, |
| intptr_t capture_count, |
| const String& pattern) { |
| macro_assembler->set_slow_safe(false /* use_slow_safe_regexp_compiler */); |
| macro_assembler_ = macro_assembler; |
| |
| ZoneGrowableArray<RegExpNode*> work_list(0); |
| work_list_ = &work_list; |
| BlockLabel fail; |
| macro_assembler_->PushBacktrack(&fail); |
| Trace new_trace; |
| start->Emit(this, &new_trace); |
| macro_assembler_->BindBlock(&fail); |
| macro_assembler_->Fail(); |
| while (!work_list.is_empty()) { |
| work_list.RemoveLast()->Emit(this, &new_trace); |
| } |
| if (reg_exp_too_big_) return IrregexpRegExpTooBig(); |
| |
| TypedData& bytecode = TypedData::ZoneHandle(macro_assembler->GetBytecode()); |
| return RegExpEngine::CompilationResult(&bytecode, next_register_); |
| } |
| |
| bool Trace::DeferredAction::Mentions(intptr_t 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(intptr_t reg) { |
| for (DeferredAction* action = actions_; action != NULL; |
| action = action->next()) { |
| if (action->Mentions(reg)) return true; |
| } |
| return false; |
| } |
| |
| bool Trace::GetStoredPosition(intptr_t reg, intptr_t* cp_offset) { |
| ASSERT(*cp_offset == 0); |
| 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; |
| } |
| |
| // 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. |
| intptr_t Trace::FindAffectedRegisters(OutSet* affected_registers, Zone* zone) { |
| intptr_t 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 (intptr_t 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, |
| intptr_t max_register, |
| const OutSet& registers_to_pop, |
| const OutSet& registers_to_clear) { |
| for (intptr_t reg = max_register; reg >= 0; reg--) { |
| if (registers_to_pop.Get(reg)) { |
| assembler->PopRegister(reg); |
| } else if (registers_to_clear.Get(reg)) { |
| intptr_t clear_to = reg; |
| while (reg > 0 && registers_to_clear.Get(reg - 1)) { |
| reg--; |
| } |
| assembler->ClearRegisters(reg, clear_to); |
| } |
| } |
| } |
| |
| void Trace::PerformDeferredActions(RegExpMacroAssembler* assembler, |
| intptr_t max_register, |
| const OutSet& affected_registers, |
| OutSet* registers_to_pop, |
| OutSet* registers_to_clear, |
| Zone* zone) { |
| for (intptr_t 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 { ACTION_IGNORE, ACTION_RESTORE, ACTION_CLEAR }; |
| DeferredActionUndoType undo_action = ACTION_IGNORE; |
| |
| intptr_t value = 0; |
| bool absolute = false; |
| bool clear = false; |
| static const intptr_t kNoStore = kMinInt32; |
| intptr_t store_position = kNoStore; |
| // 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 ACTION_IGNORE if we know there is no |
| // value to restore. |
| undo_action = ACTION_RESTORE; |
| ASSERT(store_position == kNoStore); |
| ASSERT(!clear); |
| break; |
| } |
| case ActionNode::INCREMENT_REGISTER: |
| if (!absolute) { |
| value++; |
| } |
| ASSERT(store_position == kNoStore); |
| ASSERT(!clear); |
| undo_action = ACTION_RESTORE; |
| break; |
| case ActionNode::STORE_POSITION: { |
| Trace::DeferredCapture* pc = |
| static_cast<Trace::DeferredCapture*>(action); |
| if (!clear && store_position == kNoStore) { |
| 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 = ACTION_IGNORE; |
| } else { |
| undo_action = pc->is_capture() ? ACTION_CLEAR : ACTION_RESTORE; |
| } |
| ASSERT(!absolute); |
| ASSERT(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 == kNoStore) { |
| clear = true; |
| } |
| undo_action = ACTION_RESTORE; |
| ASSERT(!absolute); |
| ASSERT(value == 0); |
| break; |
| } |
| default: |
| UNREACHABLE(); |
| break; |
| } |
| } |
| } |
| // Prepare for the undo-action (e.g., push if it's going to be popped). |
| if (undo_action == ACTION_RESTORE) { |
| assembler->PushRegister(reg); |
| registers_to_pop->Set(reg, zone); |
| } else if (undo_action == ACTION_CLEAR) { |
| registers_to_clear->Set(reg, zone); |
| } |
| // Perform the chronologically last action (or accumulated increment) |
| // for the register. |
| if (store_position != kNoStore) { |
| 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(); |
| |
| ASSERT(!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(); |
| } |
| Zone* zone = successor->zone(); |
| intptr_t max_register = FindAffectedRegisters(&affected_registers, zone); |
| OutSet registers_to_pop; |
| OutSet registers_to_clear; |
| PerformDeferredActions(assembler, max_register, affected_registers, |
| ®isters_to_pop, ®isters_to_clear, zone); |
| if (cp_offset_ != 0) { |
| assembler->AdvanceCurrentPosition(cp_offset_); |
| } |
| |
| // Create a new trivial state and generate the node with that. |
| BlockLabel undo; |
| assembler->PushBacktrack(&undo); |
| Trace new_state; |
| successor->Emit(compiler, &new_state); |
| |
| // On backtrack we need to restore state. |
| assembler->BindBlock(&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->BindBlock(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->BindBlock(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) ZoneGrowableArray<Guard*>(1); |
| guards_->Add(guard); |
| } |
| |
| ActionNode* ActionNode::SetRegister(intptr_t reg, |
| intptr_t 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(intptr_t 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(intptr_t 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(intptr_t stack_reg, |
| intptr_t 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(intptr_t stack_reg, |
| intptr_t position_reg, |
| intptr_t clear_register_count, |
| intptr_t 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(intptr_t start_register, |
| intptr_t repetition_register, |
| intptr_t 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: |
| ASSERT(!trace->mentions_reg(guard->reg())); |
| macro_assembler->IfRegisterGE(guard->reg(), guard->value(), |
| trace->backtrack()); |
| break; |
| case Guard::GEQ: |
| ASSERT(!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 intptr_t GetCaseIndependentLetters(uint16_t character, |
| bool one_byte_subject, |
| int32_t* letters) { |
| unibrow::Mapping<unibrow::Ecma262UnCanonicalize> jsregexp_uncanonicalize; |
| intptr_t length = 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 <= Symbols::kMaxOneCharCodeSymbol) { |
| 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(Zone* zone, |
| RegExpCompiler* compiler, |
| uint16_t c, |
| BlockLabel* on_failure, |
| intptr_t 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(Zone* zone, |
| RegExpCompiler* compiler, |
| uint16_t c, |
| BlockLabel* on_failure, |
| intptr_t cp_offset, |
| bool check, |
| bool preloaded) { |
| RegExpMacroAssembler* macro_assembler = compiler->macro_assembler(); |
| bool one_byte = compiler->one_byte(); |
| int32_t chars[unibrow::Ecma262UnCanonicalize::kMaxWidth]; |
| intptr_t length = GetCaseIndependentLetters(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 > Symbols::kMaxOneCharCodeSymbol) { |
| // 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, |
| uint16_t c1, |
| uint16_t c2, |
| BlockLabel* on_failure) { |
| uint16_t char_mask; |
| if (one_byte) { |
| char_mask = Symbols::kMaxOneCharCodeSymbol; |
| } else { |
| char_mask = Utf16::kMaxCodeUnit; |
| } |
| uint16_t 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. |
| ASSERT(c2 > c1); |
| uint16_t mask = char_mask ^ exor; |
| macro_assembler->CheckNotCharacterAfterAnd(c1, mask, on_failure); |
| return true; |
| } |
| ASSERT(c2 > c1); |
| uint16_t 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. |
| uint16_t mask = char_mask ^ diff; |
| macro_assembler->CheckNotCharacterAfterMinusAnd(c1 - diff, diff, mask, |
| on_failure); |
| return true; |
| } |
| return false; |
| } |
| |
| typedef bool EmitCharacterFunction(Zone* zone, |
| RegExpCompiler* compiler, |
| uint16_t c, |
| BlockLabel* on_failure, |
| intptr_t cp_offset, |
| bool check, |
| bool preloaded); |
| |
| // Only emits letters (things that have case). Only used for case independent |
| // matches. |
| static inline bool EmitAtomLetter(Zone* zone, |
| RegExpCompiler* compiler, |
| uint16_t c, |
| BlockLabel* on_failure, |
| intptr_t cp_offset, |
| bool check, |
| bool preloaded) { |
| RegExpMacroAssembler* macro_assembler = compiler->macro_assembler(); |
| bool one_byte = compiler->one_byte(); |
| int32_t chars[unibrow::Ecma262UnCanonicalize::kMaxWidth]; |
| intptr_t length = GetCaseIndependentLetters(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); |
| } |
| BlockLabel ok; |
| ASSERT(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->BindBlock(&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->BindBlock(&ok); |
| break; |
| default: |
| UNREACHABLE(); |
| break; |
| } |
| return true; |
| } |
| |
| static void EmitBoundaryTest(RegExpMacroAssembler* masm, |
| uint16_t border, |
| BlockLabel* fall_through, |
| BlockLabel* above_or_equal, |
| BlockLabel* 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, |
| uint16_t first, |
| uint16_t last, |
| BlockLabel* fall_through, |
| BlockLabel* in_range, |
| BlockLabel* 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, |
| ZoneGrowableArray<uint16_t>* ranges, |
| intptr_t start_index, |
| intptr_t end_index, |
| uint16_t min_char, |
| BlockLabel* fall_through, |
| BlockLabel* even_label, |
| BlockLabel* odd_label) { |
| static const intptr_t kSize = RegExpMacroAssembler::kTableSize; |
| static const intptr_t kMask = RegExpMacroAssembler::kTableMask; |
| |
| intptr_t base = (min_char & ~kMask); |
| |
| // Assert that everything is on one kTableSize page. |
| for (intptr_t i = start_index; i <= end_index; i++) { |
| ASSERT((ranges->At(i) & ~kMask) == base); |
| } |
| ASSERT(start_index == 0 || (ranges->At(start_index - 1) & ~kMask) <= base); |
| |
| char templ[kSize]; |
| BlockLabel* on_bit_set; |
| BlockLabel* on_bit_clear; |
| intptr_t 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 (intptr_t i = 0; i < (ranges->At(start_index) & kMask) && i < kSize; |
| i++) { |
| templ[i] = bit; |
| } |
| intptr_t j = 0; |
| bit ^= 1; |
| for (intptr_t 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 (intptr_t i = j; i < kSize; i++) { |
| templ[i] = bit; |
| } |
| // TODO(erikcorry): Cache these. |
| const TypedData& ba = TypedData::ZoneHandle( |
| masm->zone(), TypedData::New(kTypedDataUint8ArrayCid, kSize, Heap::kOld)); |
| for (intptr_t i = 0; i < kSize; i++) { |
| ba.SetUint8(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, |
| ZoneGrowableArray<uint16_t>* ranges, |
| intptr_t start_index, |
| intptr_t end_index, |
| intptr_t cut_index, |
| BlockLabel* even_label, |
| BlockLabel* odd_label) { |
| bool odd = (((cut_index - start_index) & 1) == 1); |
| BlockLabel* in_range_label = odd ? odd_label : even_label; |
| BlockLabel dummy; |
| EmitDoubleBoundaryTest(masm, ranges->At(cut_index), |
| ranges->At(cut_index + 1) - 1, &dummy, in_range_label, |
| &dummy); |
| ASSERT(!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 (intptr_t j = cut_index; j > start_index; j--) { |
| (*ranges)[j] = ranges->At(j - 1); |
| } |
| for (intptr_t j = cut_index + 1; j < end_index; j++) { |
| (*ranges)[j] = ranges->At(j + 1); |
| } |
| } |
| |
| // Unicode case. Split the search space into kSize spaces that are handled |
| // with recursion. |
| static void SplitSearchSpace(ZoneGrowableArray<uint16_t>* ranges, |
| intptr_t start_index, |
| intptr_t end_index, |
| intptr_t* new_start_index, |
| intptr_t* new_end_index, |
| uint16_t* border) { |
| static const intptr_t kSize = RegExpMacroAssembler::kTableSize; |
| static const intptr_t kMask = RegExpMacroAssembler::kTableMask; |
| |
| uint16_t first = ranges->At(start_index); |
| uint16_t 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). |
| intptr_t 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 > Symbols::kMaxOneCharCodeSymbol && // 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) { |
| intptr_t scan_forward_for_section_border = binary_chop_index; |
| intptr_t 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++; |
| } |
| } |
| |
| ASSERT(*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, |
| ZoneGrowableArray<uint16_t>* ranges, |
| intptr_t start_index, |
| intptr_t end_index, |
| uint16_t min_char, |
| uint16_t max_char, |
| BlockLabel* fall_through, |
| BlockLabel* even_label, |
| BlockLabel* odd_label) { |
| uint16_t first = ranges->At(start_index); |
| uint16_t last = ranges->At(end_index) - 1; |
| |
| ASSERT(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 intptr_t kNoCutIndex = -1; |
| intptr_t cut = kNoCutIndex; |
| for (intptr_t 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); |
| ASSERT(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 intptr_t 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; |
| } |
| |
| intptr_t new_start_index = 0; |
| intptr_t new_end_index = 0; |
| uint16_t border = 0; |
| |
| SplitSearchSpace(ranges, start_index, end_index, &new_start_index, |
| &new_end_index, &border); |
| |
| BlockLabel handle_rest; |
| BlockLabel* 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; |
| ASSERT(new_end_index == end_index - 1); |
| } |
| |
| ASSERT(start_index <= new_end_index); |
| ASSERT(new_start_index <= end_index); |
| ASSERT(start_index < new_start_index); |
| ASSERT(new_end_index < end_index); |
| ASSERT(new_end_index + 1 == new_start_index || |
| (new_end_index + 2 == new_start_index && |
| border == ranges->At(new_end_index + 1))); |
| ASSERT(min_char < border - 1); |
| ASSERT(border < max_char); |
| ASSERT(ranges->At(new_end_index) < border); |
| ASSERT(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)); |
| ASSERT(new_start_index == 0 || border >= ranges->At(new_start_index - 1)); |
| |
| masm->CheckCharacterGT(border - 1, above); |
| BlockLabel dummy; |
| GenerateBranches(masm, ranges, start_index, new_end_index, min_char, |
| border - 1, &dummy, even_label, odd_label); |
| |
| if (handle_rest.is_linked()) { |
| masm->BindBlock(&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, |
| BlockLabel* on_failure, |
| intptr_t cp_offset, |
| bool check_offset, |
| bool preloaded, |
| Zone* zone) { |
| ZoneGrowableArray<CharacterRange>* ranges = cc->ranges(); |
| if (!CharacterRange::IsCanonical(ranges)) { |
| CharacterRange::Canonicalize(ranges); |
| } |
| |
| uint16_t max_char; |
| if (one_byte) { |
| max_char = Symbols::kMaxOneCharCodeSymbol; |
| } else { |
| max_char = Utf16::kMaxCodeUnit; |
| } |
| |
| intptr_t range_count = ranges->length(); |
| |
| intptr_t last_valid_range = range_count - 1; |
| while (last_valid_range >= 0) { |
| const 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 (!preloaded) { |
| macro_assembler->LoadCurrentCharacter(cp_offset, on_failure, check_offset); |
| } |
| |
| if (cc->is_standard() && 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). |
| ZoneGrowableArray<uint16_t>* range_boundaries = |
| new (zone) ZoneGrowableArray<uint16_t>(last_valid_range); |
| |
| bool zeroth_entry_is_failure = !cc->is_negated(); |
| |
| for (intptr_t i = 0; i <= last_valid_range; i++) { |
| const CharacterRange& range = ranges->At(i); |
| if (range.from() == 0) { |
| ASSERT(i == 0); |
| zeroth_entry_is_failure = !zeroth_entry_is_failure; |
| } else { |
| range_boundaries->Add(range.from()); |
| } |
| if (range.to() + 1 <= max_char) { |
| range_boundaries->Add(range.to() + 1); |
| } |
| } |
| intptr_t end_index = range_boundaries->length() - 1; |
| |
| BlockLabel 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->BindBlock(&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->BindBlock(&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 (kRegexpOptimization && 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; |
| } |
| |
| intptr_t ActionNode::EatsAtLeast(intptr_t still_to_find, |
| intptr_t 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(intptr_t offset, |
| intptr_t 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); |
| } |
| |
| intptr_t AssertionNode::EatsAtLeast(intptr_t still_to_find, |
| intptr_t 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(intptr_t offset, |
| intptr_t 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); |
| } |
| |
| intptr_t BackReferenceNode::EatsAtLeast(intptr_t still_to_find, |
| intptr_t budget, |
| bool not_at_start) { |
| if (read_backward()) return 0; |
| if (budget <= 0) return 0; |
| return on_success()->EatsAtLeast(still_to_find, budget - 1, not_at_start); |
| } |
| |
| intptr_t TextNode::EatsAtLeast(intptr_t still_to_find, |
| intptr_t budget, |
| bool not_at_start) { |
| if (read_backward()) return 0; |
| intptr_t 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); |
| } |
| |
| intptr_t NegativeLookaroundChoiceNode::EatsAtLeast(intptr_t still_to_find, |
| intptr_t 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_)[1].node(); |
| return node->EatsAtLeast(still_to_find, budget - 1, not_at_start); |
| } |
| |
| void NegativeLookaroundChoiceNode::GetQuickCheckDetails( |
| QuickCheckDetails* details, |
| RegExpCompiler* compiler, |
| intptr_t filled_in, |
| bool not_at_start) { |
| // Alternative 0 is the negative lookahead, alternative 1 is what comes |
| // afterwards. |
| RegExpNode* node = (*alternatives_)[1].node(); |
| return node->GetQuickCheckDetails(details, compiler, filled_in, not_at_start); |
| } |
| |
| intptr_t ChoiceNode::EatsAtLeastHelper(intptr_t still_to_find, |
| intptr_t budget, |
| RegExpNode* ignore_this_node, |
| bool not_at_start) { |
| if (budget <= 0) return 0; |
| intptr_t min = 100; |
| intptr_t choice_count = alternatives_->length(); |
| budget = (budget - 1) / choice_count; |
| for (intptr_t i = 0; i < choice_count; i++) { |
| RegExpNode* node = (*alternatives_)[i].node(); |
| if (node == ignore_this_node) continue; |
| intptr_t 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; |
| } |
| |
| intptr_t LoopChoiceNode::EatsAtLeast(intptr_t still_to_find, |
| intptr_t budget, |
| bool not_at_start) { |
| return EatsAtLeastHelper(still_to_find, budget - 1, loop_node_, not_at_start); |
| } |
| |
| intptr_t ChoiceNode::EatsAtLeast(intptr_t still_to_find, |
| intptr_t 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 = Symbols::kMaxOneCharCodeSymbol; |
| } else { |
| char_mask = Utf16::kMaxCodeUnit; |
| } |
| mask_ = 0; |
| value_ = 0; |
| intptr_t char_shift = 0; |
| for (intptr_t i = 0; i < characters_; i++) { |
| Position* pos = &positions_[i]; |
| if ((pos->mask & Symbols::kMaxOneCharCodeSymbol) != 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, |
| BlockLabel* 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; |
| ASSERT(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()) { |
| ASSERT(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 = Symbols::kMaxOneCharCodeSymbol; |
| } else { |
| char_mask = Utf16::kMaxCodeUnit; |
| } |
| 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, |
| intptr_t characters_filled_in, |
| bool not_at_start) { |
| #if defined(__GNUC__) && defined(__BYTE_ORDER__) |
| // TODO(zerny): Make the combination code byte-order independent. |
| ASSERT(details->characters() == 1 || |
| (__BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__)); |
| #endif |
| // Do not collect any quick check details if the text node reads backward, |
| // since it reads in the opposite direction than we use for quick checks. |
| if (read_backward()) return; |
| ASSERT(characters_filled_in < details->characters()); |
| intptr_t characters = details->characters(); |
| int32_t char_mask; |
| if (compiler->one_byte()) { |
| char_mask = Symbols::kMaxOneCharCodeSymbol; |
| } else { |
| char_mask = Utf16::kMaxCodeUnit; |
| } |
| for (intptr_t k = 0; k < elms_->length(); k++) { |
| TextElement elm = elms_->At(k); |
| if (elm.text_type() == TextElement::ATOM) { |
| ZoneGrowableArray<uint16_t>* quarks = elm.atom()->data(); |
| for (intptr_t i = 0; i < characters && i < quarks->length(); i++) { |
| QuickCheckDetails::Position* pos = |
| details->positions(characters_filled_in); |
| uint16_t c = quarks->At(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 (elm.atom()->ignore_case()) { |
| int32_t chars[unibrow::Ecma262UnCanonicalize::kMaxWidth]; |
| intptr_t length = |
| GetCaseIndependentLetters(c, compiler->one_byte(), chars); |
| ASSERT(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 (intptr_t 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++; |
| ASSERT(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(); |
| ZoneGrowableArray<CharacterRange>* ranges = tree->ranges(); |
| ASSERT(!ranges->is_empty()); |
| 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 { |
| intptr_t 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); |
| uint16_t from = range.from(); |
| uint16_t 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 (intptr_t i = first_range + 1; i < ranges->length(); i++) { |
| CharacterRange range = ranges->At(i); |
| uint16_t from = range.from(); |
| uint16_t 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++; |
| ASSERT(characters_filled_in <= details->characters()); |
| if (characters_filled_in == details->characters()) { |
| return; |
| } |
| } |
| } |
| ASSERT(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(intptr_t by, bool one_byte) { |
| if (by >= characters_ || by < 0) { |
| // check that by < 0 => characters_ == 0 |
| ASSERT(by >= 0 || characters_ == 0); |
| Clear(); |
| return; |
| } |
| for (intptr_t i = 0; i < characters_ - by; i++) { |
| positions_[i] = positions_[by + i]; |
| } |
| for (intptr_t 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, intptr_t from_index) { |
| ASSERT(characters_ == other->characters_); |
| if (other->cannot_match_) { |
| return; |
| } |
| if (cannot_match_) { |
| *this = *other; |
| return; |
| } |
| for (intptr_t 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; |
| uint16_t differing_bits = (pos->value ^ other_pos->value); |
| pos->mask &= ~differing_bits; |
| pos->value &= pos->mask; |
| } |
| } |
| |
| class VisitMarker : public ValueObject { |
| public: |
| explicit VisitMarker(NodeInfo* info) : info_(info) { |
| ASSERT(!info->visited); |
| info->visited = true; |
| } |
| ~VisitMarker() { info_->visited = false; } |
| |
| private: |
| NodeInfo* info_; |
| }; |
| |
| RegExpNode* SeqRegExpNode::FilterOneByte(intptr_t depth) { |
| if (info()->replacement_calculated) return replacement(); |
| if (depth < 0) return this; |
| ASSERT(!info()->visited); |
| VisitMarker marker(info()); |
| return FilterSuccessor(depth - 1); |
| } |
| |
| RegExpNode* SeqRegExpNode::FilterSuccessor(intptr_t depth) { |
| RegExpNode* next = on_success_->FilterOneByte(depth - 1); |
| 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( |
| ZoneGrowableArray<CharacterRange>* ranges) { |
| for (intptr_t i = 0; i < ranges->length(); i++) { |
| // TODO(dcarney): this could be a lot more efficient. |
| if (RangeContainsLatin1Equivalents(ranges->At(i))) return true; |
| } |
| return false; |
| } |
| |
| static uint16_t ConvertNonLatin1ToLatin1(uint16_t c) { |
| ASSERT(c > Symbols::kMaxOneCharCodeSymbol); |
| switch (c) { |
| // This are equivalent characters in unicode. |
| case 0x39c: |
| case 0x3bc: |
| return 0xb5; |
| // This is an uppercase of a Latin-1 character |
| // outside of Latin-1. |
| case 0x178: |
| return 0xff; |
| } |
| return 0; |
| } |
| |
| RegExpNode* TextNode::FilterOneByte(intptr_t depth) { |
| if (info()->replacement_calculated) return replacement(); |
| if (depth < 0) return this; |
| ASSERT(!info()->visited); |
| VisitMarker marker(info()); |
| intptr_t element_count = elms_->length(); |
| for (intptr_t i = 0; i < element_count; i++) { |
| TextElement elm = elms_->At(i); |
| if (elm.text_type() == TextElement::ATOM) { |
| ZoneGrowableArray<uint16_t>* quarks = elm.atom()->data(); |
| for (intptr_t j = 0; j < quarks->length(); j++) { |
| uint16_t c = quarks->At(j); |
| if (c <= Symbols::kMaxOneCharCodeSymbol) continue; |
| if (!elm.atom()->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 = ConvertNonLatin1ToLatin1(c); |
| // Character is outside Latin-1 completely |
| if (converted == 0) return set_replacement(NULL); |
| // Convert quark to Latin-1 in place. |
| (*quarks)[0] = converted; |
| } |
| } else { |
| ASSERT(elm.text_type() == TextElement::CHAR_CLASS); |
| RegExpCharacterClass* cc = elm.char_class(); |
| ZoneGrowableArray<CharacterRange>* ranges = cc->ranges(); |
| if (!CharacterRange::IsCanonical(ranges)) { |
| CharacterRange::Canonicalize(ranges); |
| } |
| // Now they are in order so we only need to look at the first. |
| intptr_t range_count = ranges->length(); |
| if (cc->is_negated()) { |
| if (range_count != 0 && ranges->At(0).from() == 0 && |
| ranges->At(0).to() >= Symbols::kMaxOneCharCodeSymbol) { |
| // This will be handled in a later filter. |
| if (cc->flags().IgnoreCase() && |
| RangesContainLatin1Equivalents(ranges)) { |
| continue; |
| } |
| return set_replacement(NULL); |
| } |
| } else { |
| if (range_count == 0 || |
| ranges->At(0).from() > Symbols::kMaxOneCharCodeSymbol) { |
| // This will be handled in a later filter. |
| if (cc->flags().IgnoreCase() && |
| RangesContainLatin1Equivalents(ranges)) |
| continue; |
| return set_replacement(NULL); |
| } |
| } |
| } |
| } |
| return FilterSuccessor(depth - 1); |
| } |
| |
| RegExpNode* LoopChoiceNode::FilterOneByte(intptr_t depth) { |
| 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); |
| // 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); |
| } |
| |
| RegExpNode* ChoiceNode::FilterOneByte(intptr_t depth) { |
| if (info()->replacement_calculated) return replacement(); |
| if (depth < 0) return this; |
| if (info()->visited) return this; |
| VisitMarker marker(info()); |
| intptr_t choice_count = alternatives_->length(); |
| |
| for (intptr_t i = 0; i < choice_count; i++) { |
| GuardedAlternative alternative = alternatives_->At(i); |
| if (alternative.guards() != NULL && alternative.guards()->length() != 0) { |
| set_replacement(this); |
| return this; |
| } |
| } |
| |
| intptr_t surviving = 0; |
| RegExpNode* survivor = NULL; |
| for (intptr_t i = 0; i < choice_count; i++) { |
| GuardedAlternative alternative = alternatives_->At(i); |
| RegExpNode* replacement = alternative.node()->FilterOneByte(depth - 1); |
| ASSERT(replacement != this); // No missing EMPTY_MATCH_CHECK. |
| if (replacement != NULL) { |
| (*alternatives_)[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. |
| ZoneGrowableArray<GuardedAlternative>* new_alternatives = |
| new (Z) ZoneGrowableArray<GuardedAlternative>(surviving); |
| for (intptr_t i = 0; i < choice_count; i++) { |
| RegExpNode* replacement = |
| (*alternatives_)[i].node()->FilterOneByte(depth - 1); |
| if (replacement != NULL) { |
| (*alternatives_)[i].set_node(replacement); |
| new_alternatives->Add((*alternatives_)[i]); |
| } |
| } |
| alternatives_ = new_alternatives; |
| return this; |
| } |
| |
| RegExpNode* NegativeLookaroundChoiceNode::FilterOneByte(intptr_t depth) { |
| 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_)[1].node(); |
| RegExpNode* replacement = node->FilterOneByte(depth - 1); |
| if (replacement == NULL) return set_replacement(NULL); |
| (*alternatives_)[1].set_node(replacement); |
| |
| RegExpNode* neg_node = (*alternatives_)[0].node(); |
| RegExpNode* neg_replacement = neg_node->FilterOneByte(depth - 1); |
| // 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_)[0].set_node(neg_replacement); |
| return set_replacement(this); |
| } |
| |
| void LoopChoiceNode::GetQuickCheckDetails(QuickCheckDetails* details, |
| RegExpCompiler* compiler, |
| intptr_t 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(intptr_t offset, |
| intptr_t 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, |
| intptr_t characters_filled_in, |
| bool not_at_start) { |
| not_at_start = (not_at_start || not_at_start_); |
| intptr_t choice_count = alternatives_->length(); |
| ASSERT(choice_count > 0); |
| (*alternatives_)[0].node()->GetQuickCheckDetails( |
| details, compiler, characters_filled_in, not_at_start); |
| for (intptr_t i = 1; i < choice_count; i++) { |
| QuickCheckDetails new_details(details->characters()); |
| RegExpNode* node = (*alternatives_)[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, |
| BlockLabel* word, |
| BlockLabel* 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(); |
| |
| BlockLabel 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->BindBlock(&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) { |
| intptr_t eats_at_least = |
| Utils::Minimum(kMaxLookaheadForBoyerMoore, |
| EatsAtLeast(kMaxLookaheadForBoyerMoore, kRecursionBudget, |
| not_at_start)); |
| if (eats_at_least >= 1) { |
| BoyerMooreLookahead* bm = |
| new (Z) BoyerMooreLookahead(eats_at_least, compiler, Z); |
| 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) { |
| BlockLabel before_non_word; |
| BlockLabel 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->BindBlock(&before_non_word); |
| BlockLabel ok; |
| // Backtrack on \B (non-boundary check) if previous is a word, |
| // since we know next *is not* a word and this would be a boundary. |
| BacktrackIfPrevious(compiler, trace, at_boundary ? kIsNonWord : kIsWord); |
| |
| if (!assembler->IsClosed()) { |
| assembler->GoTo(&ok); |
| } |
| |
| assembler->BindBlock(&before_word); |
| BacktrackIfPrevious(compiler, trace, at_boundary ? kIsWord : kIsNonWord); |
| assembler->BindBlock(&ok); |
| } else if (next_is_word_character == Trace::TRUE_VALUE) { |
| BacktrackIfPrevious(compiler, trace, at_boundary ? kIsWord : kIsNonWord); |
| } else { |
| ASSERT(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(); |
| |
| BlockLabel fall_through, dummy; |
| |
| BlockLabel* non_word = backtrack_if_previous == kIsNonWord |
| ? new_trace.backtrack() |
| : &fall_through; |
| BlockLabel* 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->BindBlock(&fall_through); |
| on_success()->Emit(compiler, &new_trace); |
| } |
| |
| void AssertionNode::GetQuickCheckDetails(QuickCheckDetails* details, |
| RegExpCompiler* compiler, |
| intptr_t 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: { |
| BlockLabel ok; |
| assembler->CheckPosition(trace->cp_offset(), &ok); |
| assembler->GoTo(trace->backtrack()); |
| assembler->BindBlock(&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->cp_offset(), trace->backtrack()); |
| Trace at_start_trace = *trace; |
| at_start_trace.set_at_start(Trace::TRUE_VALUE); |
| 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, intptr_t offset) { |
| if (quick_check == NULL) return false; |
| if (offset >= quick_check->characters()) return false; |
| return quick_check->positions(offset)->determines_perfectly; |
| } |
| |
| static void UpdateBoundsCheck(intptr_t index, intptr_t* 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, |
| intptr_t* checked_up_to) { |
| RegExpMacroAssembler* assembler = compiler->macro_assembler(); |
| bool one_byte = compiler->one_byte(); |
| BlockLabel* backtrack = trace->backtrack(); |
| QuickCheckDetails* quick_check = trace->quick_check_performed(); |
| intptr_t element_count = elms_->length(); |
| intptr_t backward_offset = read_backward() ? -Length() : 0; |
| for (intptr_t i = preloaded ? 0 : element_count - 1; i >= 0; i--) { |
| TextElement elm = elms_->At(i); |
| intptr_t cp_offset = trace->cp_offset() + elm.cp_offset() + backward_offset; |
| if (elm.text_type() == TextElement::ATOM) { |
| ZoneGrowableArray<uint16_t>* quarks = elm.atom()->data(); |
| for (intptr_t j = preloaded ? 0 : quarks->length() - 1; j >= 0; j--) { |
| if (SkipPass(pass, elm.atom()->ignore_case())) continue; |
| if (first_element_checked && i == 0 && j == 0) continue; |
| if (DeterminedAlready(quick_check, elm.cp_offset() + j)) continue; |
| EmitCharacterFunction* emit_function = NULL; |
| uint16_t quark = quarks->At(j); |
| if (elm.atom()->ignore_case()) { |
| // Everywhere else we assume that a non-Latin-1 character cannot match |
| // a Latin-1 character. Avoid the cases where this is assumption is |
| // invalid by using the Latin1 equivalent instead. |
| quark = Latin1::TryConvertToLatin1(quark); |
| } |
| switch (pass) { |
| case NON_LATIN1_MATCH: |
| ASSERT(one_byte); |
| if (quark > Symbols::kMaxOneCharCodeSymbol) { |
| 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) { |
| const bool bounds_check = |
| *checked_up_to < (cp_offset + j) || read_backward(); |
| bool bound_checked = |
| emit_function(Z, compiler, quarks->At(j), backtrack, |
| cp_offset + j, bounds_check, preloaded); |
| if (bound_checked) UpdateBoundsCheck(cp_offset + j, checked_up_to); |
| } |
| } |
| } else { |
| ASSERT(elm.text_type() == TextElement::CHAR_CLASS); |
| 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(); |
| bool bounds_check = *checked_up_to < cp_offset || read_backward(); |
| EmitCharClass(assembler, cc, one_byte, backtrack, cp_offset, |
| bounds_check, preloaded, Z); |
| UpdateBoundsCheck(cp_offset, checked_up_to); |
| } |
| } |
| } |
| } |
| |
| intptr_t TextNode::Length() { |
| TextElement elm = elms_->Last(); |
| ASSERT(elm.cp_offset() >= 0); |
| return elm.cp_offset() + elm.length(); |
| } |
| |
| bool TextNode::SkipPass(intptr_t intptr_t_pass, bool ignore_case) { |
| TextEmitPassType pass = static_cast<TextEmitPassType>(intptr_t_pass); |
| if (ignore_case) { |
| return pass == SIMPLE_CHARACTER_MATCH; |
| } else { |
| return pass == NON_LETTER_CHARACTER_MATCH || pass == CASE_CHARACTER_MATCH; |
| } |
| } |
| |
| TextNode* TextNode::CreateForCharacterRanges( |
| ZoneGrowableArray<CharacterRange>* ranges, |
| bool read_backward, |
| RegExpNode* on_success, |
| RegExpFlags flags) { |
| ASSERT(ranges != nullptr); |
| ZoneGrowableArray<TextElement>* elms = new ZoneGrowableArray<TextElement>(1); |
| elms->Add(TextElement::CharClass(new RegExpCharacterClass(ranges, flags))); |
| return new TextNode(elms, read_backward, on_success); |
| } |
| |
| TextNode* TextNode::CreateForSurrogatePair(CharacterRange lead, |
| CharacterRange trail, |
| bool read_backward, |
| RegExpNode* on_success, |
| RegExpFlags flags) { |
| auto lead_ranges = CharacterRange::List(on_success->zone(), lead); |
| auto trail_ranges = CharacterRange::List(on_success->zone(), trail); |
| auto elms = new ZoneGrowableArray<TextElement>(2); |
| |
| elms->Add( |
| TextElement::CharClass(new RegExpCharacterClass(lead_ranges, flags))); |
| elms->Add( |
| TextElement::CharClass(new RegExpCharacterClass(trail_ranges, flags))); |
| |
| return new TextNode(elms, read_backward, on_success); |
| } |
| |
| // 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; |
| ASSERT(limit_result == CONTINUE); |
| |
| if (trace->cp_offset() + Length() > RegExpMacroAssembler::kMaxCPOffset) { |
| compiler->SetRegExpTooBig(); |
| return; |
| } |
| |
| if (compiler->one_byte()) { |
| intptr_t dummy = 0; |
| TextEmitPass(compiler, NON_LATIN1_MATCH, false, trace, false, &dummy); |
| } |
| |
| bool first_elt_done = false; |
| intptr_t 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 (intptr_t pass = kFirstRealPass; pass <= kLastPass; pass++) { |
| TextEmitPass(compiler, static_cast<TextEmitPassType>(pass), true, trace, |
| false, &bound_checked_to); |
| } |
| first_elt_done = true; |
| } |
| |
| for (intptr_t pass = kFirstRealPass; pass <= kLastPass; pass++) { |
| TextEmitPass(compiler, static_cast<TextEmitPassType>(pass), false, trace, |
| first_elt_done, &bound_checked_to); |
| } |
| |
| Trace successor_trace(*trace); |
| // If we advance backward, we may end up at the start. |
| successor_trace.AdvanceCurrentPositionInTrace( |
| read_backward() ? -Length() : Length(), compiler); |
| successor_trace.set_at_start(read_backward() ? Trace::UNKNOWN |
| : Trace::FALSE_VALUE); |
| RecursionCheck rc(compiler); |
| on_success()->Emit(compiler, &successor_trace); |
| } |
| |
| void Trace::InvalidateCurrentCharacter() { |
| characters_preloaded_ = 0; |
| } |
| |
| void Trace::AdvanceCurrentPositionInTrace(intptr_t by, |
| RegExpCompiler* compiler) { |
| // 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_ = |
| Utils::Maximum(static_cast<intptr_t>(0), bound_checked_up_to_ - by); |
| } |
| |
| void TextNode::MakeCaseIndependent(bool is_one_byte) { |
| intptr_t element_count = elms_->length(); |
| for (intptr_t i = 0; i < element_count; i++) { |
| TextElement elm = elms_->At(i); |
| if (elm.text_type() == TextElement::CHAR_CLASS) { |
| RegExpCharacterClass* cc = elm.char_class(); |
| bool case_equivalents_already_added = |
| cc->flags().NeedsUnicodeCaseEquivalents(); |
| if (cc->flags().IgnoreCase() && !case_equivalents_already_added) { |
| // 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()) continue; |
| CharacterRange::AddCaseEquivalents(cc->ranges(), is_one_byte, Z); |
| } |
| } |
| } |
| } |
| |
| intptr_t TextNode::GreedyLoopTextLength() { |
| TextElement elm = elms_->At(elms_->length() - 1); |
| return elm.cp_offset() + elm.length(); |
| } |
| |
| RegExpNode* TextNode::GetSuccessorOfOmnivorousTextNode( |
| RegExpCompiler* compiler) { |
| if (read_backward()) return nullptr; |
| 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(); |
| ZoneGrowableArray<CharacterRange>* ranges = node->ranges(); |
| 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 = Symbols::kMaxOneCharCodeSymbol; |
| } else { |
| max_char = Utf16::kMaxCodeUnit; |
| } |
| 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. |
| intptr_t ChoiceNode::GreedyLoopTextLengthForAlternative( |
| const GuardedAlternative* alternative) { |
| intptr_t 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. |
| intptr_t recursion_depth = 0; |
| while (node != this) { |
| if (recursion_depth++ > RegExpCompiler::kMaxRecursion) { |
| return kNodeIsTooComplexForGreedyLoops; |
| } |
| intptr_t 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 read_backward() ? -length : length; |
| } |
| |
| void LoopChoiceNode::AddLoopAlternative(GuardedAlternative alt) { |
| ASSERT(loop_node_ == NULL); |
| AddAlternative(alt); |
| loop_node_ = alt.node(); |
| } |
| |
| void LoopChoiceNode::AddContinueAlternative(GuardedAlternative alt) { |
| ASSERT(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. |
| intptr_t text_length = |
| GreedyLoopTextLengthForAlternative(&alternatives_->At(0)); |
| ASSERT(text_length != kNodeIsTooComplexForGreedyLoops); |
| // Update the counter-based backtracking info on the stack. This is an |
| // optimization for greedy loops (see below). |
| ASSERT(trace->cp_offset() == text_length); |
| macro_assembler->AdvanceCurrentPosition(text_length); |
| macro_assembler->GoTo(trace->loop_label()); |
| return; |
| } |
| ASSERT(trace->stop_node() == NULL); |
| if (!trace->is_trivial()) { |
| trace->Flush(compiler, this); |
| return; |
| } |
| ChoiceNode::Emit(compiler, trace); |
| } |
| |
| intptr_t ChoiceNode::CalculatePreloadCharacters(RegExpCompiler* compiler, |
| intptr_t eats_at_least) { |
| intptr_t preload_characters = |
| Utils::Minimum(static_cast<intptr_t>(4), eats_at_least); |
| if (compiler->one_byte()) { |
| #if !defined(DART_COMPRESSED_POINTERS) && !defined(TARGET_ARCH_RISCV32) |
| 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 |
| // Ensure LoadCodeUnitsInstr can always produce a Smi. See |
| // https://github.com/dart-lang/sdk/issues/29951 |
| if (preload_characters > 2) preload_characters = 2; |
| #endif |
| } else { |
| #if !defined(DART_COMPRESSED_POINTERS) && !defined(TARGET_ARCH_RISCV32) |
| if (preload_characters > 2) preload_characters = 2; |
| #else |
| // Ensure LoadCodeUnitsInstr can always produce a Smi. See |
| // https://github.com/dart-lang/sdk/issues/29951 |
| if (preload_characters > 1) preload_characters = 1; |
| #endif |
| } |
| if (!compiler->macro_assembler()->CanReadUnaligned()) { |
| if (preload_characters > 1) preload_characters = 1; |
| } |
| return preload_characters; |
| } |
| |
| // This structure is used when generating the alternatives in a choice node. It |
| // records the way the alternative is being code generated. |
| struct AlternativeGeneration { |
| AlternativeGeneration() |
| : possible_success(), |
| expects_preload(false), |
| after(), |
| quick_check_details() {} |
| BlockLabel possible_success; |
| bool expects_preload; |
| BlockLabel 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: |
| explicit AlternativeGenerationList(intptr_t count) : count_(count) { |
| ASSERT(count >= 0); |
| if (count > kAFew) { |
| excess_alt_gens_.reset(new AlternativeGeneration[count - kAFew]); |
| } |
| } |
| |
| AlternativeGeneration* at(intptr_t i) { |
| ASSERT(0 <= i); |
| ASSERT(i < count_); |
| if (i < kAFew) { |
| return &a_few_alt_gens_[i]; |
| } |
| return &excess_alt_gens_[i - kAFew]; |
| } |
| |
| private: |
| static const intptr_t kAFew = 10; |
| |
| intptr_t count_; |
| AlternativeGeneration a_few_alt_gens_[kAFew]; |
| std::unique_ptr<AlternativeGeneration[]> excess_alt_gens_; |
| |
| DISALLOW_ALLOCATION(); |
| DISALLOW_COPY_AND_ASSIGN(AlternativeGenerationList); |
| }; |
| |
| static const int32_t kRangeEndMarker = Utf::kMaxCodePoint + 1; |
| |
| // The '2' variant is 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. |
| // 0x180E has been removed from Unicode's Zs category and thus |
| // from ECMAScript's WhiteSpace category as of Unicode 6.3. |
| static const int32_t kSpaceRanges[] = { |
| '\t', '\r' + 1, ' ', ' ' + 1, 0x00A0, 0x00A1, 0x1680, |
| 0x1681, 0x2000, 0x200B, 0x2028, 0x202A, 0x202F, 0x2030, |
| 0x205F, 0x2060, 0x3000, 0x3001, 0xFEFF, 0xFF00, kRangeEndMarker}; |
| static const intptr_t kSpaceRangeCount = ARRAY_SIZE(kSpaceRanges); |
| static const int32_t kWordRanges[] = { |
| '0', '9' + 1, 'A', 'Z' + 1, '_', '_' + 1, 'a', 'z' + 1, kRangeEndMarker}; |
| static const intptr_t kWordRangeCount = ARRAY_SIZE(kWordRanges); |
| static const int32_t kDigitRanges[] = {'0', '9' + 1, kRangeEndMarker}; |
| static const intptr_t kDigitRangeCount = ARRAY_SIZE(kDigitRanges); |
| static const int32_t kSurrogateRanges[] = {0xd800, 0xe000, kRangeEndMarker}; |
| static const intptr_t kSurrogateRangeCount = ARRAY_SIZE(kSurrogateRanges); |
| static const int32_t kLineTerminatorRanges[] = { |
| 0x000A, 0x000B, 0x000D, 0x000E, 0x2028, 0x202A, kRangeEndMarker}; |
| static const intptr_t kLineTerminatorRangeCount = |
| ARRAY_SIZE(kLineTerminatorRanges); |
| |
| void BoyerMoorePositionInfo::Set(intptr_t 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 (intptr_t i = 0; i < kMapSize; i++) |
| (*map_)[i] = true; |
| } |
| return; |
| } |
| for (intptr_t i = interval.from(); i <= interval.to(); i++) { |
| intptr_t mod_character = (i & kMask); |
| if (!map_->At(mod_character)) { |
| map_count_++; |
| (*map_)[mod_character] = true; |
| } |
| if (map_count_ == kMapSize) return; |
| } |
| } |
| |
| void BoyerMoorePositionInfo::SetAll() { |
| s_ = w_ = d_ = kLatticeUnknown; |
| if (map_count_ != kMapSize) { |
| map_count_ = kMapSize; |
| for (intptr_t i = 0; i < kMapSize; i++) |
| (*map_)[i] = true; |
| } |
| } |
| |
| BoyerMooreLookahead::BoyerMooreLookahead(intptr_t length, |
| RegExpCompiler* compiler, |
| Zone* zone) |
| : length_(length), compiler_(compiler) { |
| if (compiler->one_byte()) { |
| max_char_ = Symbols::kMaxOneCharCodeSymbol; |
| } else { |
| max_char_ = Utf16::kMaxCodeUnit; |
| } |
| bitmaps_ = new (zone) ZoneGrowableArray<BoyerMoorePositionInfo*>(length); |
| for (intptr_t i = 0; i < length; i++) { |
| bitmaps_->Add(new (zone) BoyerMoorePositionInfo(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(intptr_t* from, intptr_t* to) { |
| intptr_t 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 intptr_t kMaxMax = 32; |
| for (intptr_t 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. |
| intptr_t BoyerMooreLookahead::FindBestInterval(intptr_t max_number_of_chars, |
| intptr_t old_biggest_points, |
| intptr_t* from, |
| intptr_t* to) { |
| intptr_t biggest_points = old_biggest_points; |
| static const intptr_t kSize = RegExpMacroAssembler::kTableSize; |
| for (intptr_t i = 0; i < length_;) { |
| while (i < length_ && Count(i) > max_number_of_chars) |
| i++; |
| if (i == length_) break; |
| intptr_t remembered_from = i; |
| bool union_map[kSize]; |
| for (intptr_t j = 0; j < kSize; j++) |
| union_map[j] = false; |
| while (i < length_ && Count(i) <= max_number_of_chars) { |
| BoyerMoorePositionInfo* map = bitmaps_->At(i); |
| for (intptr_t j = 0; j < kSize; j++) |
| union_map[j] |= map->at(j); |
| i++; |
| } |
| intptr_t frequency = 0; |
| for (intptr_t 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. |
| intptr_t probability = |
| (in_quickcheck_range ? kSize / 2 : kSize) - frequency; |
| intptr_t 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. |
| intptr_t BoyerMooreLookahead::GetSkipTable( |
| intptr_t min_lookahead, |
| intptr_t max_lookahead, |
| const TypedData& boolean_skip_table) { |
| const intptr_t kSize = RegExpMacroAssembler::kTableSize; |
| |
| const intptr_t kSkipArrayEntry = 0; |
| const intptr_t kDontSkipArrayEntry = 1; |
| |
| for (intptr_t i = 0; i < kSize; i++) { |
| boolean_skip_table.SetUint8(i, kSkipArrayEntry); |
| } |
| intptr_t skip = max_lookahead + 1 - min_lookahead; |
| |
| for (intptr_t i = max_lookahead; i >= min_lookahead; i--) { |
| BoyerMoorePositionInfo* map = bitmaps_->At(i); |
| for (intptr_t j = 0; j < kSize; j++) { |
| if (map->at(j)) { |
| boolean_skip_table.SetUint8(j, kDontSkipArrayEntry); |
| } |
| } |
| } |
| |
| return skip; |
| } |
| |
| // See comment above on the implementation of GetSkipTable. |
| void BoyerMooreLookahead::EmitSkipInstructions(RegExpMacroAssembler* masm) { |
| const intptr_t kSize = RegExpMacroAssembler::kTableSize; |
| |
| intptr_t min_lookahead = 0; |
| intptr_t max_lookahead = 0; |
| |
| if (!FindWorthwhileInterval(&min_lookahead, &max_lookahead)) return; |
| |
| bool found_single_character = false; |
| intptr_t single_character = 0; |
| for (intptr_t 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 (intptr_t j = 0; j < kSize; j++) { |
| if (map->at(j)) { |
| found_single_character = true; |
| single_character = j; |
| break; |
| } |
| } |
| } |
| |
| intptr_t 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) { |
| BlockLabel cont, again; |
| masm->BindBlock(&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->BindBlock(&cont); |
| return; |
| } |
| |
| const TypedData& boolean_skip_table = TypedData::ZoneHandle( |
| compiler_->zone(), |
| TypedData::New(kTypedDataUint8ArrayCid, kSize, Heap::kOld)); |
| intptr_t skip_distance = |
| GetSkipTable(min_lookahead, max_lookahead, boolean_skip_table); |
| ASSERT(skip_distance != 0); |
| |
| BlockLabel cont, again; |
| |
| masm->BindBlock(&again); |
| masm->CheckPreemption(/*is_backtrack=*/false); |
| masm->LoadCurrentCharacter(max_lookahead, &cont, true); |
| masm->CheckBitInTable(boolean_skip_table, &cont); |
| masm->AdvanceCurrentPosition(skip_distance); |
| masm->GoTo(&again); |
| masm->BindBlock(&cont); |
| |
| return; |
| } |
| |
| /* 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(Trace::FALSE_VALUE); |
| } |
| |
| void ChoiceNode::AssertGuardsMentionRegisters(Trace* trace) { |
| #ifdef DEBUG |
| intptr_t choice_count = alternatives_->length(); |
| for (intptr_t i = 0; i < choice_count - 1; i++) { |
| GuardedAlternative alternative = alternatives_->At(i); |
| ZoneGrowableArray<Guard*>* guards = alternative.guards(); |
| intptr_t guard_count = (guards == NULL) ? 0 : guards->length(); |
| for (intptr_t j = 0; j < guard_count; j++) { |
| ASSERT(!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) { |
| intptr_t choice_count = alternatives_->length(); |
| |
| if (choice_count == 1 && alternatives_->At(0).guards() == nullptr) { |
| alternatives_->At(0).node()->Emit(compiler, trace); |
| return; |
| } |
| |
| AssertGuardsMentionRegisters(trace); |
| |
| LimitResult limit_result = LimitVersions(compiler, trace); |
| if (limit_result == DONE) return; |
| ASSERT(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()); |
| |
| intptr_t text_length = |
| GreedyLoopTextLengthForAlternative(&alternatives_->At(0)); |
| AlternativeGenerationList alt_gens(choice_count); |
| |
| 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. |
| BlockLabel second_choice; |
| compiler->macro_assembler()->BindBlock(&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. |
| intptr_t new_flush_budget = trace->flush_budget() / choice_count; |
| for (intptr_t 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, |
| intptr_t 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. |
| ASSERT(trace->stop_node() == NULL); |
| macro_assembler->PushCurrentPosition(); |
| BlockLabel greedy_match_failed; |
| Trace greedy_match_trace; |
| if (not_at_start()) greedy_match_trace.set_at_start(Trace::FALSE_VALUE); |
| greedy_match_trace.set_backtrack(&greedy_match_failed); |
| BlockLabel loop_label; |
| macro_assembler->BindBlock(&loop_label); |
| macro_assembler->CheckPreemption(/*is_backtrack=*/false); |
| greedy_match_trace.set_stop_node(this); |
| greedy_match_trace.set_loop_label(&loop_label); |
| (*alternatives_)[0].node()->Emit(compiler, &greedy_match_trace); |
| macro_assembler->BindBlock(&greedy_match_failed); |
| |
| BlockLabel second_choice; // For use in greedy matches. |
| macro_assembler->BindBlock(&second_choice); |
| |
| Trace* new_trace = greedy_loop_state->counter_backtrack_trace(); |
| |
| EmitChoices(compiler, alt_gens, 1, new_trace, preload); |
| |
| macro_assembler->BindBlock(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; |
| } |
| |
| intptr_t ChoiceNode::EmitOptimizedUnanchoredSearch(RegExpCompiler* compiler, |
| Trace* trace) { |
| intptr_t 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. |
| ASSERT(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 = Utils::Minimum( |
| kMaxLookaheadForBoyerMoore, |
| EatsAtLeast(kMaxLookaheadForBoyerMoore, kRecursionBudget, false)); |
| if (eats_at_least >= 1) { |
| bm = new (Z) BoyerMooreLookahead(eats_at_least, compiler, Z); |
| 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, |
| intptr_t 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. |
| intptr_t choice_count = alternatives_->length(); |
| |
| intptr_t new_flush_budget = trace->flush_budget() / choice_count; |
| |
| for (intptr_t 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_); |
| ZoneGrowableArray<Guard*>* guards = alternative.guards(); |
| intptr_t 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 (kRegexpOptimization && |
| 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->BindBlock(&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 (intptr_t 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->BindBlock(&alt_gen->after); |
| } |
| } |
| |
| void ChoiceNode::EmitOutOfLineContinuation(RegExpCompiler* compiler, |
| Trace* trace, |
| GuardedAlternative alternative, |
| AlternativeGeneration* alt_gen, |
| intptr_t preload_characters, |
| bool next_expects_preload) { |
| if (!alt_gen->possible_success.is_linked()) return; |
| |
| RegExpMacroAssembler* macro_assembler = compiler->macro_assembler(); |
| macro_assembler->BindBlock(&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); |
| ZoneGrowableArray<Guard*>* guards = alternative.guards(); |
| intptr_t guard_count = (guards == NULL) ? 0 : guards->length(); |
| if (next_expects_preload) { |
| BlockLabel reload_current_char; |
| out_of_line_trace.set_backtrack(&reload_current_char); |
| for (intptr_t 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->BindBlock(&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 (intptr_t 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; |
| ASSERT(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: { |
| intptr_t start_pos_reg = data_.u_empty_match_check.start_register; |
| intptr_t stored_pos = 0; |
| intptr_t 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 { |
| BlockLabel 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) { |
| intptr_t 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->BindBlock(&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); |
| intptr_t clear_register_count = data_.u_submatch.clear_register_count; |
| if (clear_register_count == 0) { |
| on_success()->Emit(compiler, trace); |
| return; |
| } |
| intptr_t clear_registers_from = data_.u_submatch.clear_register_from; |
| BlockLabel clear_registers_backtrack; |
| Trace new_trace = *trace; |
| new_trace.set_backtrack(&clear_registers_backtrack); |
| on_success()->Emit(compiler, &new_trace); |
| |
| assembler->BindBlock(&clear_registers_backtrack); |
| intptr_t clear_registers_to = |
| clear_registers_from + clear_register_count - 1; |
| assembler->ClearRegisters(clear_registers_from, clear_registers_to); |
| |
| ASSERT(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; |
| ASSERT(limit_result == CONTINUE); |
| |
| RecursionCheck rc(compiler); |
| |
| ASSERT(start_reg_ + 1 == end_reg_); |
| if (flags_.IgnoreCase()) { |
| assembler->CheckNotBackReferenceIgnoreCase( |
| start_reg_, read_backward(), flags_.IsUnicode(), trace->backtrack()); |
| } else { |
| assembler->CheckNotBackReference(start_reg_, read_backward(), |
| trace->backtrack()); |
| } |
| // We are going to advance backward, so we may end up at the start. |
| if (read_backward()) trace->set_at_start(Trace::UNKNOWN); |
| |
| // Check that the back reference does not end inside a surrogate pair. |
| if (flags_.IsUnicode() && !compiler->one_byte()) { |
| assembler->CheckNotInSurrogatePair(trace->cp_offset(), trace->backtrack()); |
| } |
| |
| on_success()->Emit(compiler, trace); |
| } |
| |
| // ------------------------------------------------------------------- |
| // Dot/dotty output |
| |
| #ifdef DEBUG |
| |
| class DotPrinter : public NodeVisitor { |
| public: |
| explicit DotPrinter(bool 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 |
| }; |
| |
| void DotPrinter::PrintNode(const char* label, RegExpNode* node) { |
| OS::PrintErr("digraph G {\n graph [label=\""); |
| for (intptr_t i = 0; label[i] != '\0'; i++) { |
| switch (label[i]) { |
| case '\\': |
| OS::PrintErr("\\\\"); |
| break; |
| case '"': |
| OS::PrintErr("\""); |
| break; |
| default: |
| OS::PrintErr("%c", label[i]); |
| break; |
| } |
| } |
| OS::PrintErr("\"];\n"); |
| Visit(node); |
| OS::PrintErr("}\n"); |
| } |
| |
| 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::PrintErr(" n%p -> n%p [style=dotted];\n", from, on_failure); |
| Visit(on_failure); |
| } |
| |
| class AttributePrinter : public ValueObject { |
| public: |
| AttributePrinter() : first_(true) {} |
| void PrintSeparator() { |
| if (first_) { |
| first_ = false; |
| } else { |
| OS::PrintErr("|"); |
| } |
| } |
| void PrintBit(const char* name, bool value) { |
| if (!value) return; |
| PrintSeparator(); |
| OS::PrintErr("{%s}", name); |
| } |
| void PrintPositive(const char* name, intptr_t value) { |
| if (value < 0) return; |
| PrintSeparator(); |
| OS::PrintErr("{%s|%" Pd "}", name, value); |
| } |
| |
| private: |
| bool first_; |
| }; |
| |
| void DotPrinter::PrintAttributes(RegExpNode* that) { |
| OS::PrintErr( |
| " a%p [shape=Mrecord, color=grey, fontcolor=grey, " |
| "margin=0.1, fontsize=10, label=\"{", |
| that); |
| AttributePrinter printer; |
| 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); |
| BlockLabel* label = that->label(); |
| if (label->is_bound()) printer.PrintPositive("@", label->pos()); |
| OS::PrintErr( |
| "}\"];\n" |
| " a%p -> n%p [style=dashed, color=grey, arrowhead=none];\n", |
| that, that); |
| } |
| |
| void DotPrinter::VisitChoice(ChoiceNode* that) { |
| OS::PrintErr(" n%p [shape=Mrecord, label=\"?\"];\n", that); |
| for (intptr_t i = 0; i < that->alternatives()->length(); i++) { |
| GuardedAlternative alt = that->alternatives()->At(i); |
| OS::PrintErr(" n%p -> n%p", that, alt.node()); |
| } |
| for (intptr_t i = 0; i < that->alternatives()->length(); i++) { |
| GuardedAlternative alt = that->alternatives()->At(i); |
| alt.node()->Accept(this); |
| } |
| } |
| |
| void DotPrinter::VisitText(TextNode* that) { |
| OS::PrintErr(" n%p [label=\"", that); |
| for (intptr_t i = 0; i < that->elements()->length(); i++) { |
| if (i > 0) OS::PrintErr(" "); |
| TextElement elm = that->elements()->At(i); |
| switch (elm.text_type()) { |
| case TextElement::ATOM: { |
| ZoneGrowableArray<uint16_t>* data = elm.atom()->data(); |
| for (intptr_t i = 0; i < data->length(); i++) { |
| OS::PrintErr("%c", static_cast<char>(data->At(i))); |
| } |
| break; |
| } |
| case TextElement::CHAR_CLASS: { |
| RegExpCharacterClass* node = elm.char_class(); |
| OS::PrintErr("["); |
| if (node->is_negated()) OS::PrintErr("^"); |
| for (intptr_t j = 0; j < node->ranges()->length(); j++) { |
| CharacterRange range = node->ranges()->At(j); |
| PrintUtf16(range.from()); |
| OS::PrintErr("-"); |
| PrintUtf16(range.to()); |
| } |
| OS::PrintErr("]"); |
| break; |
| } |
| default: |
| UNREACHABLE(); |
| } |
| } |
| OS::PrintErr("\", shape=box, peripheries=2];\n"); |
| PrintAttributes(that); |
| OS::PrintErr(" n%p -> n%p;\n", that, that->on_success()); |
| Visit(that->on_success()); |
| } |
| |
| void DotPrinter::VisitBackReference(BackReferenceNode* that) { |
| OS::PrintErr(" n%p [label=\"$%" Pd "..$%" Pd "\", shape=doubleoctagon];\n", |
| that, that->start_register(), that->end_register()); |
| PrintAttributes(that); |
| OS::PrintErr(" n%p -> n%p;\n", that, that->on_success()); |
| Visit(that->on_success()); |
| } |
| |
| void DotPrinter::VisitEnd(EndNode* that) { |
| OS::PrintErr(" n%p [style=bold, shape=point];\n", that); |
| PrintAttributes(that); |
| } |
| |
| void DotPrinter::VisitAssertion(AssertionNode* that) { |
| OS::PrintErr(" n%p [", that); |
| switch (that->assertion_type()) { |
| case AssertionNode::AT_END: |
| OS::PrintErr("label=\"$\", shape=septagon"); |
| break; |
| case AssertionNode::AT_START: |
| OS::PrintErr("label=\"^\", shape=septagon"); |
| break; |
| case AssertionNode::AT_BOUNDARY: |
| OS::PrintErr("label=\"\\b\", shape=septagon"); |
| break; |
| case AssertionNode::AT_NON_BOUNDARY: |
| OS::PrintErr("label=\"\\B\", shape=septagon"); |
| break; |
| case AssertionNode::AFTER_NEWLINE: |
| OS::PrintErr("label=\"(?<=\\n)\", shape=septagon"); |
| break; |
| } |
| OS::PrintErr("];\n"); |
| PrintAttributes(that); |
| RegExpNode* successor = that->on_success(); |
| OS::PrintErr(" n%p -> n%p;\n", that, successor); |
| Visit(successor); |
| } |
| |
| void DotPrinter::VisitAction(ActionNode* that) { |
| OS::PrintErr(" n%p [", that); |
| switch (that->action_type_) { |
| case ActionNode::SET_REGISTER: |
| OS::PrintErr("label=\"$%" Pd ":=%" Pd "\", shape=octagon", |
| that->data_.u_store_register.reg, |
| that->data_.u_store_register.value); |
| break; |
| case ActionNode::INCREMENT_REGISTER: |
| OS::PrintErr("label=\"$%" Pd "++\", shape=octagon", |
| that->data_.u_increment_register.reg); |
| break; |
| case ActionNode::STORE_POSITION: |
| OS::PrintErr("label=\"$%" Pd ":=$pos\", shape=octagon", |
| that->data_.u_position_register.reg); |
| break; |
| case ActionNode::BEGIN_SUBMATCH: |
| OS::PrintErr("label=\"$%" Pd ":=$pos,begin\", shape=septagon", |
| that->data_.u_submatch.current_position_register); |
| break; |
| case ActionNode::POSITIVE_SUBMATCH_SUCCESS: |
| OS::PrintErr("label=\"escape\", shape=septagon"); |
| break; |
| case ActionNode::EMPTY_MATCH_CHECK: |
| OS::PrintErr("label=\"$%" Pd "=$pos?,$%" Pd "<%" Pd "?\", shape=septagon", |
| that->data_.u_empty_match_check.start_register, |
| that->data_.u_empty_match_check.repetition_register, |
| that->data_.u_empty_match_check.repetition_limit); |
| break; |
| case ActionNode::CLEAR_CAPTURES: { |
| OS::PrintErr("label=\"clear $%" Pd " to $%" Pd "\", shape=septagon", |
| that->data_.u_clear_captures.range_from, |
| that->data_.u_clear_captures.range_to); |
| break; |
| } |
| } |
| OS::PrintErr("];\n"); |
| PrintAttributes(that); |
| RegExpNode* successor = that->on_success(); |
| OS::PrintErr(" n%p -> n%p;\n", that, successor); |
| Visit(successor); |
| } |
| |
| void RegExpEngine::DotPrint(const char* label, |
| RegExpNode* node, |
| bool ignore_case) { |
| DotPrinter printer(ignore_case); |
| printer.PrintNode(label, node); |
| } |
| |
| #endif // DEBUG |
| |
| // ------------------------------------------------------------------- |
| // Tree to graph conversion |
| |
| // The zone in which we allocate graph nodes. |
| #define OZ (on_success->zone()) |
| |
| RegExpNode* RegExpAtom::ToNode(RegExpCompiler* compiler, |
| RegExpNode* on_success) { |
| ZoneGrowableArray<TextElement>* elms = |
| new (OZ) ZoneGrowableArray<TextElement>(1); |
| elms->Add(TextElement::Atom(this)); |
| return new (OZ) TextNode(elms, compiler->read_backward(), on_success); |
| } |
| |
| RegExpNode* RegExpText::ToNode(RegExpCompiler* compiler, |
| RegExpNode* on_success) { |
| ZoneGrowableArray<TextElement>* elms = |
| new (OZ) ZoneGrowableArray<TextElement>(1); |
| for (intptr_t i = 0; i < elements()->length(); i++) { |
| elms->Add(elements()->At(i)); |
| } |
| return new (OZ) TextNode(elms, compiler->read_backward(), on_success); |
| } |
| |
| static bool CompareInverseRanges(ZoneGrowableArray<CharacterRange>* ranges, |
| const int32_t* special_class, |
| intptr_t length) { |
| length--; // Remove final kRangeEndMarker. |
| ASSERT(special_class[length] == kRangeEndMarker); |
| ASSERT(ranges->length() != 0); |
| ASSERT(length != 0); |
| ASSERT(special_class[0] != 0); |
| if (ranges->length() != (length >> 1) + 1) { |
| return false; |
| } |
| CharacterRange range = ranges->At(0); |
| if (range.from() != 0) { |
| return false; |
| } |
| for (intptr_t 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() != Utf::kMaxCodePoint) { |
| return false; |
| } |
| return true; |
| } |
| |
| static bool CompareRanges(ZoneGrowableArray<CharacterRange>* ranges, |
| const int32_t* special_class, |
| intptr_t length) { |
| length--; // Remove final kRangeEndMarker. |
| ASSERT(special_class[length] == kRangeEndMarker); |
| if (ranges->length() * 2 != length) { |
| return false; |
| } |
| for (intptr_t 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() { |
| // 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(), kSpaceRanges, kSpaceRangeCount)) { |
| set_.set_standard_set_type('s'); |
| return true; |
| } |
| if (CompareInverseRanges(set_.ranges(), kSpaceRanges, kSpaceRangeCount)) { |
| set_.set_standard_set_type('S'); |
| return true; |
| } |
| if (CompareInverseRanges(set_.ranges(), kLineTerminatorRanges, |
| kLineTerminatorRangeCount)) { |
| set_.set_standard_set_type('.'); |
| return true; |
| } |
| if (CompareRanges(set_.ranges(), kLineTerminatorRanges, |
| kLineTerminatorRangeCount)) { |
| set_.set_standard_set_type('n'); |
| return true; |
| } |
| if (CompareRanges(set_.ranges(), kWordRanges, kWordRangeCount)) { |
| set_.set_standard_set_type('w'); |
| return true; |
| } |
| if (CompareInverseRanges(set_.ranges(), kWordRanges, kWordRangeCount)) { |
| set_.set_standard_set_type('W'); |
| return true; |
| } |
| return false; |
| } |
| |
| UnicodeRangeSplitter::UnicodeRangeSplitter( |
| Zone* zone, |
| ZoneGrowableArray<CharacterRange>* base) |
| : zone_(zone), |
| table_(zone), |
| bmp_(nullptr), |
| lead_surrogates_(nullptr), |
| trail_surrogates_(nullptr), |
| non_bmp_(nullptr) { |
| // The unicode range splitter categorizes given character ranges into: |
| // - Code points from the BMP representable by one code unit. |
| // - Code points outside the BMP that need to be split into surrogate pairs. |
| // - Lone lead surrogates. |
| // - Lone trail surrogates. |
| // Lone surrogates are valid code points, even though no actual characters. |
| // They require special matching to make sure we do not split surrogate pairs. |
| // We use the dispatch table to accomplish this. The base range is split up |
| // by the table by the overlay ranges, and the Call callback is used to |
| // filter and collect ranges for each category. |
| for (intptr_t i = 0; i < base->length(); i++) { |
| table_.AddRange(base->At(i), kBase, zone_); |
| } |
| // Add overlay ranges. |
| table_.AddRange(CharacterRange::Range(0, Utf16::kLeadSurrogateStart - 1), |
| kBmpCodePoints, zone_); |
| table_.AddRange(CharacterRange::Range(Utf16::kLeadSurrogateStart, |
| Utf16::kLeadSurrogateEnd), |
| kLeadSurrogates, zone_); |
| table_.AddRange(CharacterRange::Range(Utf16::kTrailSurrogateStart, |
| Utf16::kTrailSurrogateEnd), |
| kTrailSurrogates, zone_); |
| table_.AddRange( |
| CharacterRange::Range(Utf16::kTrailSurrogateEnd + 1, Utf16::kMaxCodeUnit), |
| kBmpCodePoints, zone_); |
| table_.AddRange( |
| CharacterRange::Range(Utf16::kMaxCodeUnit + 1, Utf::kMaxCodePoint), |
| kNonBmpCodePoints, zone_); |
| table_.ForEach(this); |
| } |
| |
| void UnicodeRangeSplitter::Call(uint32_t from, ChoiceTable::Entry entry) { |
| OutSet* outset = entry.out_set(); |
| if (!outset->Get(kBase)) return; |
| ZoneGrowableArray<CharacterRange>** target = nullptr; |
| if (outset->Get(kBmpCodePoints)) { |
| target = &bmp_; |
| } else if (outset->Get(kLeadSurrogates)) { |
| target = &lead_surrogates_; |
| } else if (outset->Get(kTrailSurrogates)) { |
| target = &trail_surrogates_; |
| } else { |
| ASSERT(outset->Get(kNonBmpCodePoints)); |
| target = &non_bmp_; |
| } |
| if (*target == nullptr) { |
| *target = new (zone_) ZoneGrowableArray<CharacterRange>(2); |
| } |
| (*target)->Add(CharacterRange::Range(entry.from(), entry.to())); |
| } |
| |
| void AddBmpCharacters(RegExpCompiler* compiler, |
| ChoiceNode* result, |
| RegExpNode* on_success, |
| UnicodeRangeSplitter* splitter) { |
| ZoneGrowableArray<CharacterRange>* bmp = splitter->bmp(); |
| if (bmp == nullptr) return; |
| result->AddAlternative(GuardedAlternative(TextNode::CreateForCharacterRanges( |
| bmp, compiler->read_backward(), on_success, RegExpFlags()))); |
| } |
| |
| void AddNonBmpSurrogatePairs(RegExpCompiler* compiler, |
| ChoiceNode* result, |
| RegExpNode* on_success, |
| UnicodeRangeSplitter* splitter) { |
| ZoneGrowableArray<CharacterRange>* non_bmp = splitter->non_bmp(); |
| if (non_bmp == nullptr) return; |
| ASSERT(!compiler->one_byte()); |
| CharacterRange::Canonicalize(non_bmp); |
| for (int i = 0; i < non_bmp->length(); i++) { |
| // Match surrogate pair. |
| // E.g. [\u10005-\u11005] becomes |
| // \ud800[\udc05-\udfff]| |
| // [\ud801-\ud803][\udc00-\udfff]| |
| // \ud804[\udc00-\udc05] |
| uint32_t from = non_bmp->At(i).from(); |
| uint32_t to = non_bmp->At(i).to(); |
| uint16_t from_points[2]; |
| Utf16::Encode(from, from_points); |
| uint16_t to_points[2]; |
| Utf16::Encode(to, to_points); |
| if (from_points[0] == to_points[0]) { |
| // The lead surrogate is the same. |
| result->AddAlternative( |
| GuardedAlternative(TextNode::CreateForSurrogatePair( |
| CharacterRange::Singleton(from_points[0]), |
| CharacterRange::Range(from_points[1], to_points[1]), |
| compiler->read_backward(), on_success, RegExpFlags()))); |
| } else { |
| if (from_points[1] != Utf16::kTrailSurrogateStart) { |
| // Add [from_l][from_t-\udfff] |
| result->AddAlternative( |
| GuardedAlternative(TextNode::CreateForSurrogatePair( |
| CharacterRange::Singleton(from_points[0]), |
| CharacterRange::Range(from_points[1], |
| Utf16::kTrailSurrogateEnd), |
| compiler->read_backward(), on_success, RegExpFlags()))); |
| from_points[0]++; |
| } |
| if (to_points[1] != Utf16::kTrailSurrogateEnd) { |
| // Add [to_l][\udc00-to_t] |
| result->AddAlternative( |
| GuardedAlternative(TextNode::CreateForSurrogatePair( |
| CharacterRange::Singleton(to_points[0]), |
| CharacterRange::Range(Utf16::kTrailSurrogateStart, |
| to_points[1]), |
| compiler->read_backward(), on_success, RegExpFlags()))); |
| to_points[0]--; |
| } |
| if (from_points[0] <= to_points[0]) { |
| // Add [from_l-to_l][\udc00-\udfff] |
| result->AddAlternative( |
| GuardedAlternative(TextNode::CreateForSurrogatePair( |
| CharacterRange::Range(from_points[0], to_points[0]), |
| CharacterRange::Range(Utf16::kTrailSurrogateStart, |
| Utf16::kTrailSurrogateEnd), |
| compiler->read_backward(), on_success, RegExpFlags()))); |
| } |
| } |
| } |
| } |
| |
| RegExpNode* NegativeLookaroundAgainstReadDirectionAndMatch( |
| RegExpCompiler* compiler, |
| ZoneGrowableArray<CharacterRange>* lookbehind, |
| ZoneGrowableArray<CharacterRange>* match, |
| RegExpNode* on_success, |
| bool read_backward, |
| RegExpFlags flags) { |
| RegExpNode* match_node = TextNode::CreateForCharacterRanges( |
| match, read_backward, on_success, flags); |
| int stack_register = compiler->UnicodeLookaroundStackRegister(); |
| int position_register = compiler->UnicodeLookaroundPositionRegister(); |
| RegExpLookaround::Builder lookaround(false, match_node, stack_register, |
| position_register); |
| RegExpNode* negative_match = TextNode::CreateForCharacterRanges( |
| lookbehind, !read_backward, lookaround.on_match_success(), flags); |
| return lookaround.ForMatch(negative_match); |
| } |
| |
| RegExpNode* MatchAndNegativeLookaroundInReadDirection( |
| RegExpCompiler* compiler, |
| ZoneGrowableArray<CharacterRange>* match, |
| ZoneGrowableArray<CharacterRange>* lookahead, |
| RegExpNode* on_success, |
| bool read_backward, |
| RegExpFlags flags) { |
| int stack_register = compiler->UnicodeLookaroundStackRegister(); |
| int position_register = compiler->UnicodeLookaroundPositionRegister(); |
| RegExpLookaround::Builder lookaround(false, on_success, stack_register, |
| position_register); |
| RegExpNode* negative_match = TextNode::CreateForCharacterRanges( |
| lookahead, read_backward, lookaround.on_match_success(), flags); |
| return TextNode::CreateForCharacterRanges( |
| match, read_backward, lookaround.ForMatch(negative_match), flags); |
| } |
| |
| void AddLoneLeadSurrogates(RegExpCompiler* compiler, |
| ChoiceNode* result, |
| RegExpNode* on_success, |
| UnicodeRangeSplitter* splitter) { |
| auto lead_surrogates = splitter->lead_surrogates(); |
| if (lead_surrogates == nullptr) return; |
| // E.g. \ud801 becomes \ud801(?![\udc00-\udfff]). |
| auto trail_surrogates = CharacterRange::List( |
| on_success->zone(), CharacterRange::Range(Utf16::kTrailSurrogateStart, |
| Utf16::kTrailSurrogateEnd)); |
| |
| RegExpNode* match; |
| if (compiler->read_backward()) { |
| // Reading backward. Assert that reading forward, there is no trail |
| // surrogate, and then backward match the lead surrogate. |
| match = NegativeLookaroundAgainstReadDirectionAndMatch( |
| compiler, trail_surrogates, lead_surrogates, on_success, true, |
| RegExpFlags()); |
| } else { |
| // Reading forward. Forward match the lead surrogate and assert that |
| // no trail surrogate follows. |
| match = MatchAndNegativeLookaroundInReadDirection( |
| compiler, lead_surrogates, trail_surrogates, on_success, false, |
| RegExpFlags()); |
| } |
| result->AddAlternative(GuardedAlternative(match)); |
| } |
| |
| void AddLoneTrailSurrogates(RegExpCompiler* compiler, |
| ChoiceNode* result, |
| RegExpNode* on_success, |
| UnicodeRangeSplitter* splitter) { |
| auto trail_surrogates = splitter->trail_surrogates(); |
| if (trail_surrogates == nullptr) return; |
| // E.g. \udc01 becomes (?<![\ud800-\udbff])\udc01 |
| auto lead_surrogates = CharacterRange::List( |
| on_success->zone(), CharacterRange::Range(Utf16::kLeadSurrogateStart, |
| Utf16::kLeadSurrogateEnd)); |
| |
| RegExpNode* match; |
| if (compiler->read_backward()) { |
| // Reading backward. Backward match the trail surrogate and assert that no |
| // lead surrogate precedes it. |
| match = MatchAndNegativeLookaroundInReadDirection( |
| compiler, trail_surrogates, lead_surrogates, on_success, true, |
| RegExpFlags()); |
| } else { |
| // Reading forward. Assert that reading backward, there is no lead |
| // surrogate, and then forward match the trail surrogate. |
| match = NegativeLookaroundAgainstReadDirectionAndMatch( |
| compiler, lead_surrogates, trail_surrogates, on_success, false, |
| RegExpFlags()); |
| } |
| result->AddAlternative(GuardedAlternative(match)); |
| } |
| |
| RegExpNode* UnanchoredAdvance(RegExpCompiler* compiler, |
| RegExpNode* on_success) { |
| // This implements ES2015 21.2.5.2.3, AdvanceStringIndex. |
| ASSERT(!compiler->read_backward()); |
| // Advance any character. If the character happens to be a lead surrogate and |
| // we advanced into the middle of a surrogate pair, it will work out, as |
| // nothing will match from there. We will have to advance again, consuming |
| // the associated trail surrogate. |
| auto range = CharacterRange::List( |
| on_success->zone(), CharacterRange::Range(0, Utf16::kMaxCodeUnit)); |
| return TextNode::CreateForCharacterRanges(range, false, on_success, |
| RegExpFlags()); |
| } |
| |
| void AddUnicodeCaseEquivalents(ZoneGrowableArray<CharacterRange>* ranges) { |
| ASSERT(CharacterRange::IsCanonical(ranges)); |
| |
| // Micro-optimization to avoid passing large ranges to UnicodeSet::closeOver. |
| // See also https://crbug.com/v8/6727. |
| // TODO(sstrickl): This only covers the special case of the {0,0x10FFFF} |
| // range, which we use frequently internally. But large ranges can also easily |
| // be created by the user. We might want to have a more general caching |
| // mechanism for such ranges. |
| if (ranges->length() == 1 && ranges->At(0).IsEverything(Utf::kMaxCodePoint)) { |
| return; |
| } |
| |
| icu::UnicodeSet set; |
| for (int i = 0; i < ranges->length(); i++) { |
| set.add(ranges->At(i).from(), ranges->At(i).to()); |
| } |
| ranges->Clear(); |
| set.closeOver(USET_CASE_INSENSITIVE); |
| // Full case mapping map single characters to multiple characters. |
| // Those are represented as strings in the set. Remove them so that |
| // we end up with only simple and common case mappings. |
| set.removeAllStrings(); |
| for (int i = 0; i < set.getRangeCount(); i++) { |
| ranges->Add( |
| CharacterRange::Range(set.getRangeStart(i), set.getRangeEnd(i))); |
| } |
| // No errors and everything we collected have been ranges. |
| CharacterRange::Canonicalize(ranges); |
| } |
| |
| RegExpNode* RegExpCharacterClass::ToNode(RegExpCompiler* compiler, |
| RegExpNode* on_success) { |
| set_.Canonicalize(); |
| ZoneGrowableArray<CharacterRange>* ranges = this->ranges(); |
| if (flags_.NeedsUnicodeCaseEquivalents()) { |
| AddUnicodeCaseEquivalents(ranges); |
| } |
| if (flags_.IsUnicode() && !compiler->one_byte() && |
| !contains_split_surrogate()) { |
| if (is_negated()) { |
| ZoneGrowableArray<CharacterRange>* negated = |
| new ZoneGrowableArray<CharacterRange>(2); |
| CharacterRange::Negate(ranges, negated); |
| ranges = negated; |
| } |
| if (ranges->length() == 0) { |
| RegExpCharacterClass* fail = |
| new RegExpCharacterClass(ranges, RegExpFlags()); |
| return new TextNode(fail, compiler->read_backward(), on_success); |
| } |
| if (standard_type() == '*') { |
| return UnanchoredAdvance(compiler, on_success); |
| } else { |
| ChoiceNode* result = new (OZ) ChoiceNode(2, OZ); |
| UnicodeRangeSplitter splitter(OZ, ranges); |
| AddBmpCharacters(compiler, result, on_success, &splitter); |
| AddNonBmpSurrogatePairs(compiler, result, on_success, &splitter); |
| AddLoneLeadSurrogates(compiler, result, on_success, &splitter); |
| AddLoneTrailSurrogates(compiler, result, on_success, &splitter); |
| return result; |
| } |
| } else { |
| return new TextNode(this, compiler->read_backward(), on_success); |
| } |
| return new (OZ) TextNode(this, compiler->read_backward(), on_success); |
| } |
| |
| RegExpNode* RegExpDisjunction::ToNode(RegExpCompiler* compiler, |
| RegExpNode* on_success) { |
| ZoneGrowableArray<RegExpTree*>* alternatives = this->alternatives(); |
| intptr_t length = alternatives->length(); |
| ChoiceNode* result = new (OZ) ChoiceNode(length, OZ); |
| for (intptr_t 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 ValueObject { |
| public: |
| static const intptr_t kMaxExpansionFactor = 6; |
| RegExpExpansionLimiter(RegExpCompiler* compiler, intptr_t factor) |
| : compiler_(compiler), |
| saved_expansion_factor_(compiler->current_expansion_factor()), |
| ok_to_expand_(saved_expansion_factor_ <= kMaxExpansionFactor) { |
| ASSERT(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 { |
| intptr_t 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_; |
| intptr_t saved_expansion_factor_; |
| bool ok_to_expand_; |
| |
| DISALLOW_IMPLICIT_CONSTRUCTORS(RegExpExpansionLimiter); |
| }; |
| |
| RegExpNode* RegExpQuantifier::ToNode(intptr_t min, |
| intptr_t 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. |
| // Unroll (foo)+ and (foo){3,} |
| static const intptr_t kMaxUnrolledMinMatches = 3; |
| // Unroll (foo)? and (foo){x,3} |
| static const intptr_t kMaxUnrolledMaxMatches = 3; |
| if (max == 0) return on_success; // This can happen due to recursion. |
| bool body_can_be_empty = (body->min_match() == 0); |
| intptr_t 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 (kRegexpOptimization && !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()) { |
| intptr_t 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 (intptr_t i = 0; i < min; i++) { |
| answer = body->ToNode(compiler, answer); |
| } |
| return answer; |
| } |
| } |
| if (max <= kMaxUnrolledMaxMatches && min == 0) { |
| ASSERT(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 (intptr_t 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 && !compiler->read_backward()) { |
| 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; |
| intptr_t reg_ctr = needs_counter ? compiler->AllocateRegister() |
| : RegExpCompiler::kNoRegister; |
| LoopChoiceNode* center = new (zone) |
| LoopChoiceNode(body->min_match() == 0, compiler->read_backward(), zone); |
| if (not_at_start && !compiler->read_backward()) 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 (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; |
| } |
| } |
| |
| namespace { |
| // Desugar \b to (?<=\w)(?=\W)|(?<=\W)(?=\w) and |
| // \B to (?<=\w)(?=\w)|(?<=\W)(?=\W) |
| RegExpNode* BoundaryAssertionAsLookaround(RegExpCompiler* compiler, |
| RegExpNode* on_success, |
| RegExpAssertion::AssertionType type, |
| RegExpFlags flags) { |
| ASSERT(flags.NeedsUnicodeCaseEquivalents()); |
| ZoneGrowableArray<CharacterRange>* word_range = |
| new ZoneGrowableArray<CharacterRange>(2); |
| CharacterRange::AddClassEscape('w', word_range, true); |
| int stack_register = compiler->UnicodeLookaroundStackRegister(); |
| int position_register = compiler->UnicodeLookaroundPositionRegister(); |
| ChoiceNode* result = new (OZ) ChoiceNode(2, OZ); |
| // Add two choices. The (non-)boundary could start with a word or |
| // a non-word-character. |
| for (int i = 0; i < 2; i++) { |
| bool lookbehind_for_word = i == 0; |
| bool lookahead_for_word = |
| (type == RegExpAssertion::BOUNDARY) ^ lookbehind_for_word; |
| // Look to the left. |
| RegExpLookaround::Builder lookbehind(lookbehind_for_word, on_success, |
| stack_register, position_register); |
| RegExpNode* backward = TextNode::CreateForCharacterRanges( |
| word_range, true, lookbehind.on_match_success(), flags); |
| // Look to the right. |
| RegExpLookaround::Builder lookahead(lookahead_for_word, |
| lookbehind.ForMatch(backward), |
| stack_register, position_register); |
| RegExpNode* forward = TextNode::CreateForCharacterRanges( |
| word_range, false, lookahead.on_match_success(), flags); |
| result->AddAlternative(GuardedAlternative(lookahead.ForMatch(forward))); |
| } |
| return result; |
| } |
| } // anonymous namespace |
| |
| RegExpNode* RegExpAssertion::ToNode(RegExpCompiler* compiler, |
| RegExpNode* on_success) { |
| switch (assertion_type()) { |
| case START_OF_LINE: |
| return AssertionNode::AfterNewline(on_success); |
| case START_OF_INPUT: |
| return AssertionNode::AtStart(on_success); |
| case BOUNDARY: |
| return flags_.NeedsUnicodeCaseEquivalents() |
| ? BoundaryAssertionAsLookaround(compiler, on_success, BOUNDARY, |
| flags_) |
| : AssertionNode::AtBoundary(on_success); |
| case NON_BOUNDARY: |
| return flags_.NeedsUnicodeCaseEquivalents() |
| ? BoundaryAssertionAsLookaround(compiler, on_success, |
| NON_BOUNDARY, flags_) |
| : 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. |
| intptr_t stack_pointer_register = compiler->AllocateRegister(); |
| intptr_t position_register = compiler->AllocateRegister(); |
| // The ChoiceNode to distinguish between a newline and end-of-input. |
| ChoiceNode* result = new ChoiceNode(2, on_success->zone()); |
| // Create a newline atom. |
| ZoneGrowableArray<CharacterRange>* newline_ranges = |
| new ZoneGrowableArray<CharacterRange>(3); |
| CharacterRange::AddClassEscape('n', newline_ranges); |
| RegExpCharacterClass* newline_atom = |
| new RegExpCharacterClass('n', RegExpFlags()); |
| TextNode* newline_matcher = |
| new TextNode(newline_atom, /*read_backwards=*/false, |
| 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 (OZ) BackReferenceNode(RegExpCapture::StartRegister(index()), |
| RegExpCapture::EndRegister(index()), flags_, |
| compiler->read_backward(), on_success); |
| } |
| |
| RegExpNode* RegExpEmpty::ToNode(RegExpCompiler* compiler, |
| RegExpNode* on_success) { |
| return on_success; |
| } |
| |
| RegExpLookaround::Builder::Builder(bool is_positive, |
| RegExpNode* on_success, |
| intptr_t stack_pointer_register, |
| intptr_t position_register, |
| intptr_t capture_register_count, |
| intptr_t capture_register_start) |
| : is_positive_(is_positive), |
| on_success_(on_success), |
| stack_pointer_register_(stack_pointer_register), |
| position_register_(position_register) { |
| if (is_positive_) { |
| on_match_success_ = ActionNode::PositiveSubmatchSuccess( |
| stack_pointer_register, position_register, capture_register_count, |
| capture_register_start, on_success); |
| } else { |
| on_match_success_ = new (OZ) NegativeSubmatchSuccess( |
| stack_pointer_register, position_register, capture_register_count, |
| capture_register_start, OZ); |
| } |
| } |
| |
| RegExpNode* RegExpLookaround::Builder::ForMatch(RegExpNode* match) { |
| if (is_positive_) { |
| return ActionNode::BeginSubmatch(stack_pointer_register_, |
| position_register_, match); |
| } else { |
| Zone* zone = on_success_->zone(); |
| // We use a ChoiceNode to represent the negative lookaround. The first |
| // alternative is the negative match. On success, the end node backtracks. |
| // On failure, the second alternative is tried and leads to success. |
| // NegativeLookaroundChoiceNode is a special ChoiceNode that ignores the |
| // first exit when calculating quick checks. |
| ChoiceNode* choice_node = new (zone) NegativeLookaroundChoiceNode( |
| GuardedAlternative(match), GuardedAlternative(on_success_), zone); |
| return ActionNode::BeginSubmatch(stack_pointer_register_, |
| position_register_, choice_node); |
| } |
| } |
| |
| RegExpNode* RegExpLookaround::ToNode(RegExpCompiler* compiler, |
| RegExpNode* on_success) { |
| intptr_t stack_pointer_register = compiler->AllocateRegister(); |
| intptr_t position_register = compiler->AllocateRegister(); |
| |
| const intptr_t registers_per_capture = 2; |
| const intptr_t register_of_first_capture = 2; |
| intptr_t register_count = capture_count_ * registers_per_capture; |
| intptr_t register_start = |
| register_of_first_capture + capture_from_ * registers_per_capture; |
| |
| RegExpNode* result; |
| bool was_reading_backward = compiler->read_backward(); |
| compiler->set_read_backward(type() == LOOKBEHIND); |
| Builder builder(is_positive(), on_success, stack_pointer_register, |
| position_register, register_count, register_start); |
| RegExpNode* match = body_->ToNode(compiler, builder.on_match_success()); |
| result = builder.ForMatch(match); |
| compiler->set_read_backward(was_reading_backward); |
| return result; |
| } |
| |
| RegExpNode* RegExpCapture::ToNode(RegExpCompiler* compiler, |
| RegExpNode* on_success) { |
| return ToNode(body(), index(), compiler, on_success); |
| } |
| |
| RegExpNode* RegExpCapture::ToNode(RegExpTree* body, |
| intptr_t index, |
| RegExpCompiler* compiler, |
| RegExpNode* on_success) { |
| ASSERT(body != nullptr); |
| intptr_t start_reg = RegExpCapture::StartRegister(index); |
| intptr_t end_reg = RegExpCapture::EndRegister(index); |
| if (compiler->read_backward()) { |
| intptr_t tmp = end_reg; |
| end_reg = start_reg; |
| start_reg = tmp; |
| } |
| 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) { |
| ZoneGrowableArray<RegExpTree*>* children = nodes(); |
| RegExpNode* current = on_success; |
| if (compiler->read_backward()) { |
| for (intptr_t i = 0; i < children->length(); i++) { |
| current = children->At(i)->ToNode(compiler, current); |
| } |
| } else { |
| for (intptr_t i = children->length() - 1; i >= 0; i--) { |
| current = children->At(i)->ToNode(compiler, current); |
| } |
| } |
| return current; |
| } |
| |
| static void AddClass(const int32_t* elmv, |
| intptr_t elmc, |
| ZoneGrowableArray<CharacterRange>* ranges) { |
| elmc--; |
| ASSERT(elmv[elmc] == kRangeEndMarker); |
| for (intptr_t i = 0; i < elmc; i += 2) { |
| ASSERT(elmv[i] < elmv[i + 1]); |
| ranges->Add(CharacterRange(elmv[i], elmv[i + 1] - 1)); |
| } |
| } |
| |
| static void AddClassNegated(const int32_t* elmv, |
| intptr_t elmc, |
| ZoneGrowableArray<CharacterRange>* ranges) { |
| elmc--; |
| ASSERT(elmv[elmc] == kRangeEndMarker); |
| ASSERT(elmv[0] != 0x0000); |
| ASSERT(elmv[elmc - 1] != Utf::kMaxCodePoint); |
| uint16_t last = 0x0000; |
| for (intptr_t i = 0; i < elmc; i += 2) { |
| ASSERT(last <= elmv[i] - 1); |
| ASSERT(elmv[i] < elmv[i + 1]); |
| ranges->Add(CharacterRange(last, elmv[i] - 1)); |
| last = elmv[i + 1]; |
| } |
| ranges->Add(CharacterRange(last, Utf::kMaxCodePoint)); |
| } |
| |
| void CharacterRange::AddClassEscape(uint16_t type, |
| ZoneGrowableArray<CharacterRange>* ranges, |
| bool add_unicode_case_equivalents) { |
| if (add_unicode_case_equivalents && (type == 'w' || type == 'W')) { |
| // See #sec-runtime-semantics-wordcharacters-abstract-operation |
| // In case of unicode and ignore_case, we need to create the closure over |
| // case equivalent characters before negating. |
| ZoneGrowableArray<CharacterRange>* new_ranges = |
| new ZoneGrowableArray<CharacterRange>(2); |
| AddClass(kWordRanges, kWordRangeCount, new_ranges); |
| AddUnicodeCaseEquivalents(new_ranges); |
| if (type == 'W') { |
| ZoneGrowableArray<CharacterRange>* negated = |
| new ZoneGrowableArray<CharacterRange>(2); |
| CharacterRange::Negate(new_ranges, negated); |
| new_ranges = negated; |
| } |
| ranges->AddArray(*new_ranges); |
| return; |
| } |
| AddClassEscape(type, ranges); |
| } |
| |
| void CharacterRange::AddClassEscape(uint16_t type, |
| ZoneGrowableArray<CharacterRange>* ranges) { |
| switch (type) { |
| case 's': |
| AddClass(kSpaceRanges, kSpaceRangeCount, ranges); |
| break; |
| case 'S': |
| AddClassNegated(kSpaceRanges, kSpaceRangeCount, ranges); |
| break; |
| case 'w': |
| AddClass(kWordRanges, kWordRangeCount, ranges); |
| break; |
| case 'W': |
| AddClassNegated(kWordRanges, kWordRangeCount, ranges); |
| break; |
| case 'd': |
| AddClass(kDigitRanges, kDigitRangeCount, ranges); |
| break; |
| case 'D': |
| AddClassNegated(kDigitRanges, kDigitRangeCount, ranges); |
| break; |
| case '.': |
| AddClassNegated(kLineTerminatorRanges, kLineTerminatorRangeCount, ranges); |
| 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()); |
| break; |
| // This is the set of characters matched by the $ and ^ symbols |
| // in multiline mode. |
| case 'n': |
| AddClass(kLineTerminatorRanges, kLineTerminatorRangeCount, ranges); |
| break; |
| default: |
| UNREACHABLE(); |
| } |
| } |
| |
| void CharacterRange::AddCaseEquivalents( |
| ZoneGrowableArray<CharacterRange>* ranges, |
| bool is_one_byte, |
| Zone* zone) { |
| CharacterRange::Canonicalize(ranges); |
| int range_count = ranges->length(); |
| for (intptr_t i = 0; i < range_count; i++) { |
| CharacterRange range = ranges->At(i); |
| int32_t bottom = range.from(); |
| if (bottom > Utf16::kMaxCodeUnit) continue; |
| int32_t top = Utils::Minimum(range.to(), Utf16::kMaxCodeUnit); |
| // Nothing to be done for surrogates |
| if (bottom >= Utf16::kLeadSurrogateStart && |
| top <= Utf16::kTrailSurrogateEnd) { |
| continue; |
| } |
| if (is_one_byte && !RangeContainsLatin1Equivalents(range)) { |
| if (bottom > Symbols::kMaxOneCharCodeSymbol) continue; |
| if (top > Symbols::kMaxOneCharCodeSymbol) { |
| top = Symbols::kMaxOneCharCodeSymbol; |
| } |
| } |
| |
| unibrow::Mapping<unibrow::Ecma262UnCanonicalize> jsregexp_uncanonicalize; |
| unibrow::Mapping<unibrow::CanonicalizationRange> jsregexp_canonrange; |
| int32_t chars[unibrow::Ecma262UnCanonicalize::kMaxWidth]; |
| if (top == bottom) { |
| // If this is a singleton we just expand the one character. |
| intptr_t length = jsregexp_uncanonicalize.get(bottom, '\0', chars); |
| for (intptr_t i = 0; i < length; i++) { |
| int32_t chr = chars[i]; |
| if (chr != bottom) { |
| ranges->Add(CharacterRange::Singleton(chars[i])); |
| } |
| } |
| } 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"). |
| int32_t range[unibrow::Ecma262UnCanonicalize::kMaxWidth]; |
| intptr_t pos = bottom; |
| while (pos <= top) { |
| intptr_t length = jsregexp_canonrange.get(pos, '\0', range); |
| int32_t block_end; |
| if (length == 0) { |
| block_end = pos; |
| } else { |
| ASSERT(length == 1); |
| block_end = range[0]; |
| } |
| intptr_t end = (block_end > top) ? top : block_end; |
| length = jsregexp_uncanonicalize.get(block_end, '\0', range); |
| for (intptr_t i = 0; i < length; i++) { |
| int32_t c = range[i]; |
| int32_t range_from = c - (block_end - pos); |
| int32_t range_to = c - (block_end - end); |
| if (!(bottom <= range_from && range_to <= top)) { |
| ranges->Add(CharacterRange(range_from, range_to)); |
| } |
| } |
| pos = end + 1; |
| } |
| } |
| } |
| } |
| |
| bool CharacterRange::IsCanonical(ZoneGrowableArray<CharacterRange>* ranges) { |
| ASSERT(ranges != NULL); |
| intptr_t n = ranges->length(); |
| if (n <= 1) return true; |
| intptr_t max = ranges->At(0).to(); |
| for (intptr_t 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; |
| } |
| |
| ZoneGrowableArray<CharacterRange>* CharacterSet::ranges() { |
| if (ranges_ == NULL) { |
| ranges_ = new ZoneGrowableArray<CharacterRange>(2); |
| CharacterRange::AddClassEscape(standard_set_type_, ranges_); |
| } |
| return ranges_; |
| } |
| |
| // Move a number of elements in a zone array to another position |
| // in the same array. Handles overlapping source and target areas. |
| static void MoveRanges(ZoneGrowableArray<CharacterRange>* list, |
| intptr_t from, |
| intptr_t to, |
| intptr_t count) { |
| // Ranges are potentially overlapping. |
| if (from < to) { |
| for (intptr_t i = count - 1; i >= 0; i--) { |
| (*list)[to + i] = list->At(from + i); |
| } |
| } else { |
| for (intptr_t i = 0; i < count; i++) { |
| (*list)[to + i] = list->At(from + i); |
| } |
| } |
| } |
| |
| static intptr_t InsertRangeInCanonicalList( |
| ZoneGrowableArray<CharacterRange>* list, |
| intptr_t 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. |
| int32_t from = insert.from(); |
| int32_t to = insert.to(); |
| intptr_t start_pos = 0; |
| intptr_t end_pos = count; |
| for (intptr_t 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)[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); |
| intptr_t new_from = Utils::Minimum(to_replace.from(), from); |
| intptr_t new_to = Utils::Maximum(to_replace.to(), to); |
| (*list)[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. |
| |
| intptr_t new_from = Utils::Minimum(list->At(start_pos).from(), from); |
| intptr_t new_to = Utils::Maximum(list->At(end_pos - 1).to(), to); |
| if (end_pos < count) { |
| MoveRanges(list, end_pos, start_pos + 1, count - end_pos); |
| } |
| (*list)[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( |
| ZoneGrowableArray<CharacterRange>* character_ranges) { |
| if (character_ranges->length() <= 1) return; |
| // Check whether ranges are already canonical (increasing, non-overlapping, |
| // non-adjacent). |
| intptr_t n = character_ranges->length(); |
| intptr_t max = character_ranges->At(0).to(); |
| intptr_t 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. |
| intptr_t read = i; // Range to insert. |
| intptr_t 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->TruncateTo(num_canonical); |
| |
| ASSERT(CharacterRange::IsCanonical(character_ranges)); |
| } |
| |
| void CharacterRange::Negate(ZoneGrowableArray<CharacterRange>* ranges, |
| ZoneGrowableArray<CharacterRange>* negated_ranges) { |
| ASSERT(CharacterRange::IsCanonical(ranges)); |
| ASSERT(negated_ranges->length() == 0); |
| intptr_t range_count = ranges->length(); |
| uint32_t from = 0; |
| intptr_t 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)); |
| from = range.to(); |
| i++; |
| } |
| if (from < Utf::kMaxCodePoint) { |
| negated_ranges->Add(CharacterRange(from + 1, Utf::kMaxCodePoint)); |
| } |
| } |
| |
| // ------------------------------------------------------------------- |
| // Splay tree |
| |
| // Workaround for the fact that ZoneGrowableArray does not have contains(). |
| static bool ArrayContains(ZoneGrowableArray<unsigned>* array, unsigned value) { |
| for (intptr_t i = 0; i < array->length(); i++) { |
| if (array->At(i) == value) { |
| return true; |
| } |
| } |
| return false; |
| } |
| |
| OutSet* OutSet::Extend(unsigned value, Zone* zone) { |
| if (Get(value)) return this; |
| if (successors() != nullptr) { |
| for (int i = 0; i < successors()->length(); i++) { |
| OutSet* successor = successors()->At(i); |
| if (successor->Get(value)) return successor; |
| } |
| } else { |
| successors_ = new (zone) ZoneGrowableArray<OutSet*>(2); |
| } |
| OutSet* result = new (zone) OutSet(first_, remaining_); |
| result->Set(value, zone); |
| successors()->Add(result); |
| return result; |
| } |
| |
| void OutSet::Set(unsigned value, Zone* zone) { |
| if (value < kFirstLimit) { |
| first_ |= (1 << value); |
| } else { |
| if (remaining_ == NULL) |
| remaining_ = new (zone) ZoneGrowableArray<unsigned>(1); |
| |
| bool remaining_contains_value = ArrayContains(remaining_, value); |
| if (remaining_->is_empty() || !remaining_contains_value) { |
| remaining_->Add(value); |
| } |
| } |
| } |
| |
| bool OutSet::Get(unsigned value) const { |
| if (value < kFirstLimit) { |
| return (first_ & (1 << value)) != 0; |
| } else if (remaining_ == NULL) { |
| return false; |
| } else { |
| return ArrayContains(remaining_, value); |
| } |
| } |
| |
| const int32_t ChoiceTable::Config::kNoKey = Utf::kInvalidChar; |
| |
| void ChoiceTable::AddRange(CharacterRange full_range, |
| int32_t 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; |
| bool inserted = tree()->Insert(current.from(), &loc); |
| ASSERT(inserted); |
| USE(inserted); |
| 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 = |
| CharacterRange::Range(entry->from(), current.from() - 1); |
| CharacterRange right = CharacterRange::Range(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; |
| bool inserted = tree()->Insert(right.from(), &loc); |
| ASSERT(inserted); |
| USE(inserted); |
| 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; |
| bool inserted = tree()->Insert(current.from(), &ins); |
| ASSERT(inserted); |
| USE(inserted); |
| ins.set_value(Entry(current.from(), entry->from() - 1, |
| empty()->Extend(value, zone))); |
| current.set_from(entry->from()); |
| } |
| ASSERT(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; |
| bool inserted = tree()->Insert(current.to() + 1, &ins); |
| ASSERT(inserted); |
| USE(inserted); |
| ins.set_value(Entry(current.to() + 1, entry->to(), entry->out_set())); |
| entry->set_to(current.to()); |
| } |
| ASSERT(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); |
| ASSERT(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; |
| bool inserted = tree()->Insert(current.from(), &ins); |
| ASSERT(inserted); |
| USE(inserted); |
| ins.set_value( |
| Entry(current.from(), current.to(), empty()->Extend(value, zone))); |
| break; |
| } |
| } |
| } |
| |
| OutSet* ChoiceTable::Get(int32_t 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) { |
| 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() { |
| intptr_t 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. |
| intptr_t cp_offset = 0; |
| for (intptr_t i = 0; i < element_count; i++) { |
| TextElement& elm = (*elements())[i]; |
| elm.set_cp_offset(cp_offset); |
| cp_offset += elm.length(); |
| } |
| } |
| |
| void Analysis::VisitText(TextNode* that) { |
| 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 (intptr_t i = 0; i < that->alternatives()->length(); i++) { |
| RegExpNode* node = (*that->alternatives())[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 (intptr_t i = 0; i < that->alternatives()->length(); i++) { |
| RegExpNode* node = (*that->alternatives())[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(intptr_t offset, |
| intptr_t 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); |
| } |
| |
| COMPILE_ASSERT(BoyerMoorePositionInfo::kMapSize == |
| RegExpMacroAssembler::kTableSize); |
| |
| void ChoiceNode::FillInBMInfo(intptr_t offset, |
| intptr_t budget, |
| BoyerMooreLookahead* bm, |
| bool not_at_start) { |
| ZoneGrowableArray<GuardedAlternative>* alts = alternatives(); |
| budget = (budget - 1) / alts->length(); |
| for (intptr_t i = 0; i < alts->length(); i++) { |
| GuardedAlternative& alt = (*alts)[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(intptr_t initial_offset, |
| intptr_t budget, |
| BoyerMooreLookahead* bm, |
| bool not_at_start) { |
| if (initial_offset >= bm->length()) return; |
| intptr_t offset = initial_offset; |
| intptr_t max_char = bm->max_char(); |
| for (intptr_t 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 (intptr_t j = 0; j < atom->length(); j++, offset++) { |
| if (offset >= bm->length()) { |
| if (initial_offset == 0) set_bm_info(not_at_start, bm); |
| return; |
| } |
| uint16_t character = atom->data()->At(j); |
| if (atom->flags().IgnoreCase()) { |
| int32_t chars[unibrow::Ecma262UnCanonicalize::kMaxWidth]; |
| intptr_t length = GetCaseIndependentLetters( |
| character, bm->max_char() == Symbols::kMaxOneCharCodeSymbol, |
| chars); |
| for (intptr_t j = 0; j < length; j++) { |
| bm->Set(offset, chars[j]); |
| } |
| } else { |
| if (character <= max_char) bm->Set(offset, character); |
| } |
| } |
| } else { |
| ASSERT(text.text_type() == TextElement::CHAR_CLASS); |
| RegExpCharacterClass* char_class = text.char_class(); |
| ZoneGrowableArray<CharacterRange>* ranges = char_class->ranges(); |
| if (char_class->is_negated()) { |
| bm->SetAll(offset); |
| } else { |
| for (intptr_t k = 0; k < ranges->length(); k++) { |
| const CharacterRange& range = ranges->At(k); |
| if (range.from() > max_char) continue; |
| intptr_t to = |
| Utils::Minimum(max_char, static_cast<intptr_t>(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); |
| } |
| |
| RegExpNode* OptionallyStepBackToLeadSurrogate(RegExpCompiler* compiler, |
| RegExpNode* on_success, |
| RegExpFlags flags) { |
| // If the regexp matching starts within a surrogate pair, step back |
| // to the lead surrogate and start matching from there. |
| ASSERT(!compiler->read_backward()); |
| Zone* zone = compiler->zone(); |
| |
| auto lead_surrogates = CharacterRange::List( |
| on_success->zone(), CharacterRange::Range(Utf16::kLeadSurrogateStart, |
| Utf16::kLeadSurrogateEnd)); |
| auto trail_surrogates = CharacterRange::List( |
| on_success->zone(), CharacterRange::Range(Utf16::kTrailSurrogateStart, |
| Utf16::kTrailSurrogateEnd)); |
| |
| ChoiceNode* optional_step_back = new (zone) ChoiceNode(2, zone); |
| |
| int stack_register = compiler->UnicodeLookaroundStackRegister(); |
| int position_register = compiler->UnicodeLookaroundPositionRegister(); |
| RegExpNode* step_back = TextNode::CreateForCharacterRanges( |
| lead_surrogates, /*read_backward=*/true, on_success, flags); |
| RegExpLookaround::Builder builder(/*is_positive=*/true, step_back, |
| stack_register, position_register); |
| RegExpNode* match_trail = TextNode::CreateForCharacterRanges( |
| trail_surrogates, /*read_backward=*/false, builder.on_match_success(), |
| flags); |
| |
| optional_step_back->AddAlternative( |
| GuardedAlternative(builder.ForMatch(match_trail))); |
| optional_step_back->AddAlternative(GuardedAlternative(on_success)); |
| |
| return optional_step_back; |
| } |
| |
| #if !defined(DART_PRECOMPILED_RUNTIME) |
| RegExpEngine::CompilationResult RegExpEngine::CompileIR( |
| RegExpCompileData* data, |
| const ParsedFunction* parsed_function, |
| const ZoneGrowableArray<const ICData*>& ic_data_array, |
| intptr_t osr_id) { |
| ASSERT(!FLAG_interpret_irregexp); |
| Zone* zone = Thread::Current()->zone(); |
| |
| const Function& function = parsed_function->function(); |
| const intptr_t specialization_cid = function.string_specialization_cid(); |
| const bool is_sticky = function.is_sticky_specialization(); |
| const bool is_one_byte = (specialization_cid == kOneByteStringCid || |
| specialization_cid == kExternalOneByteStringCid); |
| RegExp& regexp = RegExp::Handle(zone, function.regexp()); |
| const String& pattern = String::Handle(zone, regexp.pattern()); |
| |
| ASSERT(!regexp.IsNull()); |
| ASSERT(!pattern.IsNull()); |
| |
| const bool is_global = regexp.flags().IsGlobal(); |
| const bool is_unicode = regexp.flags().IsUnicode(); |
| |
| RegExpCompiler compiler(data->capture_count, is_one_byte); |
| |
| // TODO(zerny): Frequency sampling is currently disabled because of several |
| // issues. We do not want to store subject strings in the regexp object since |
| // they might be long and we should not prevent their garbage collection. |
| // Passing them to this function explicitly does not help, since we must |
| // generate exactly the same IR for both the unoptimizing and optimizing |
| // pipelines (otherwise it gets confused when i.e. deopt id's differ). |
| // An option would be to store sampling results in the regexp object, but |
| // I'm not sure the performance gains are relevant enough. |
| |
| // Wrap the body of the regexp in capture #0. |
| RegExpNode* captured_body = |
| RegExpCapture::ToNode(data->tree, 0, &compiler, compiler.accept()); |
| |
| RegExpNode* node = captured_body; |
| const bool is_end_anchored = data->tree->IsAnchoredAtEnd(); |
| const bool is_start_anchored = data->tree->IsAnchoredAtStart(); |
| intptr_t 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 is sticky. |
| RegExpNode* loop_node = RegExpQuantifier::ToNode( |
| 0, RegExpTree::kInfinity, false, |
| new (zone) RegExpCharacterClass('*', RegExpFlags()), &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('*', RegExpFlags()), |
| /*read_backwards=*/false, loop_node))); |
| node = first_step_node; |
| } else { |
| node = loop_node; |
| } |
| } |
| if (is_one_byte) { |
| node = node->FilterOneByte(RegExpCompiler::kMaxRecursion); |
| // 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); |
| } |
| } else if (is_unicode && (is_global || is_sticky)) { |
| node = OptionallyStepBackToLeadSurrogate(&compiler, node, regexp.flags()); |
| } |
| |
| if (node == NULL) node = new (zone) EndNode(EndNode::BACKTRACK, zone); |
| data->node = node; |
| Analysis analysis(is_one_byte); |
| analysis.EnsureAnalyzed(node); |
| if (analysis.has_failed()) { |
| const char* error_message = analysis.error_message(); |
| return CompilationResult(error_message); |
| } |
| |
| // Native regexp implementation. |
| |
| IRRegExpMacroAssembler* macro_assembler = new (zone) |
| IRRegExpMacroAssembler(specialization_cid, data->capture_count, |
| parsed_function, ic_data_array, osr_id, zone); |
| |
| // Inserted here, instead of in Assembler, because it depends on information |
| // in the AST that isn't replicated in the Node structure. |
| static const intptr_t kMaxBacksearchLimit = 1024; |
| if (is_end_anchored && !is_start_anchored && !is_sticky && |
| max_length < kMaxBacksearchLimit) { |
| macro_assembler->SetCurrentPositionFromEnd(max_length); |
| } |
| |
| if (is_global) { |
| RegExpMacroAssembler::GlobalMode mode = RegExpMacroAssembler::GLOBAL; |
| if (data->tree->min_match() > 0) { |
| mode = RegExpMacroAssembler::GLOBAL_NO_ZERO_LENGTH_CHECK; |
| } else if (is_unicode) { |
| mode = RegExpMacroAssembler::GLOBAL_UNICODE; |
| } |
| macro_assembler->set_global_mode(mode); |
| } |
| |
| RegExpEngine::CompilationResult result = |
| compiler.Assemble(macro_assembler, node, data->capture_count, pattern); |
| |
| if (FLAG_trace_irregexp) { |
| macro_assembler->PrintBlocks(); |
| } |
| |
| return result; |
| } |
| #endif // !defined(DART_PRECOMPILED_RUNTIME) |
| |
| RegExpEngine::CompilationResult RegExpEngine::CompileBytecode( |
| RegExpCompileData* data, |
| const RegExp& regexp, |
| bool is_one_byte, |
| bool is_sticky, |
| Zone* zone) { |
| ASSERT(FLAG_interpret_irregexp); |
| const String& pattern = String::Handle(zone, regexp.pattern()); |
| |
| ASSERT(!regexp.IsNull()); |
| ASSERT(!pattern.IsNull()); |
| |
| const bool is_global = regexp.flags().IsGlobal(); |
| const bool is_unicode = regexp.flags().IsUnicode(); |
| |
| RegExpCompiler compiler(data->capture_count, is_one_byte); |
| |
| // TODO(zerny): Frequency sampling is currently disabled because of several |
| // issues. We do not want to store subject strings in the regexp object since |
| // they might be long and we should not prevent their garbage collection. |
| // Passing them to this function explicitly does not help, since we must |
| // generate exactly the same IR for both the unoptimizing and optimizing |
| // pipelines (otherwise it gets confused when i.e. deopt id's differ). |
| // An option would be to store sampling results in the regexp object, but |
| // I'm not sure the performance gains are relevant enough. |
| |
| // 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(); |
| intptr_t 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. |
| RegExpNode* loop_node = RegExpQuantifier::ToNode( |
| 0, RegExpTree::kInfinity, false, |
| new (zone) RegExpCharacterClass('*', RegExpFlags()), &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('*', RegExpFlags()), |
| /*read_backwards=*/false, loop_node))); |
| node = first_step_node; |
| } else { |
| node = loop_node; |
| } |
| } |
| if (is_one_byte) { |
| node = node->FilterOneByte(RegExpCompiler::kMaxRecursion); |
| // 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); |
| } |
| } else if (is_unicode && (is_global || is_sticky)) { |
| node = OptionallyStepBackToLeadSurrogate(&compiler, node, regexp.flags()); |
| } |
| |
| if (node == NULL) node = new (zone) EndNode(EndNode::BACKTRACK, zone); |
| data->node = node; |
| Analysis analysis(is_one_byte); |
| analysis.EnsureAnalyzed(node); |
| if (analysis.has_failed()) { |
| const char* error_message = analysis.error_message(); |
| return CompilationResult(error_message); |
| } |
| |
| // Bytecode regexp implementation. |
| |
| ZoneGrowableArray<uint8_t> buffer(zone, 1024); |
| BytecodeRegExpMacroAssembler* macro_assembler = |
| new (zone) BytecodeRegExpMacroAssembler(&buffer, zone); |
| |
| // Inserted here, instead of in Assembler, because it depends on information |
| // in the AST that isn't replicated in the Node structure. |
| static const intptr_t kMaxBacksearchLimit = 1024; |
| if (is_end_anchored && !is_start_anchored && !is_sticky && |
| max_length < kMaxBacksearchLimit) { |
| macro_assembler->SetCurrentPositionFromEnd(max_length); |
| } |
| |
| if (is_global) { |
| RegExpMacroAssembler::GlobalMode mode = RegExpMacroAssembler::GLOBAL; |
| if (data->tree->min_match() > 0) { |
| mode = RegExpMacroAssembler::GLOBAL_NO_ZERO_LENGTH_CHECK; |
| } else if (is_unicode) { |
| mode = RegExpMacroAssembler::GLOBAL_UNICODE; |
| } |
| macro_assembler->set_global_mode(mode); |
| } |
| |
| RegExpEngine::CompilationResult result = |
| compiler.Assemble(macro_assembler, node, data->capture_count, pattern); |
| |
| if (FLAG_trace_irregexp) { |
| macro_assembler->PrintBlocks(); |
| } |
| |
| return result; |
| } |
| |
| void CreateSpecializedFunction(Thread* thread, |
| Zone* zone, |
| const RegExp& regexp, |
| intptr_t specialization_cid, |
| bool sticky, |
| const Object& owner) { |
| const intptr_t kParamCount = RegExpMacroAssembler::kParamCount; |
| |
| const FunctionType& signature = |
| FunctionType::Handle(zone, FunctionType::New()); |
| Function& fn = |
| Function::Handle(zone, Function::New(signature, Symbols::ColonMatcher(), |
| UntaggedFunction::kIrregexpFunction, |
| true, // Static. |
| false, // Not const. |
| false, // Not abstract. |
| false, // Not external. |
| false, // Not native. |
| owner, TokenPosition::kMinSource)); |
| |
| // TODO(zerny): Share these arrays between all irregexp functions. |
| // TODO(regis): Better, share a common signature. |
| signature.set_num_fixed_parameters(kParamCount); |
| signature.set_parameter_types( |
| Array::Handle(zone, Array::New(kParamCount, Heap::kOld))); |
| fn.CreateNameArray(); |
| signature.SetParameterTypeAt(RegExpMacroAssembler::kParamRegExpIndex, |
| Object::dynamic_type()); |
| fn.SetParameterNameAt(RegExpMacroAssembler::kParamRegExpIndex, |
| Symbols::This()); |
| signature.SetParameterTypeAt(RegExpMacroAssembler::kParamStringIndex, |
| Object::dynamic_type()); |
| fn.SetParameterNameAt(RegExpMacroAssembler::kParamStringIndex, |
| Symbols::string_param()); |
| signature.SetParameterTypeAt(RegExpMacroAssembler::kParamStartOffsetIndex, |
| Object::dynamic_type()); |
| fn.SetParameterNameAt(RegExpMacroAssembler::kParamStartOffsetIndex, |
| Symbols::start_index_param()); |
| signature.set_result_type(Type::Handle(zone, Type::ArrayType())); |
| |
| // Cache the result. |
| regexp.set_function(specialization_cid, sticky, fn); |
| |
| fn.SetRegExpData(regexp, specialization_cid, sticky); |
| fn.set_is_debuggable(false); |
| |
| // The function is compiled lazily during the first call. |
| } |
| |
| RegExpPtr RegExpEngine::CreateRegExp(Thread* thread, |
| const String& pattern, |
| RegExpFlags flags) { |
| Zone* zone = thread->zone(); |
| const RegExp& regexp = RegExp::Handle(RegExp::New(zone)); |
| |
| regexp.set_pattern(pattern); |
| regexp.set_flags(flags); |
| |
| // TODO(zerny): We might want to use normal string searching algorithms |
| // for simple patterns. |
| regexp.set_is_complex(); |
| regexp.set_is_global(); // All dart regexps are global. |
| |
| if (!FLAG_interpret_irregexp) { |
| const Library& lib = Library::Handle(zone, Library::CoreLibrary()); |
| const Class& owner = |
| Class::Handle(zone, lib.LookupClass(Symbols::RegExp())); |
| |
| for (intptr_t cid = kOneByteStringCid; cid <= kExternalTwoByteStringCid; |
| cid++) { |
| CreateSpecializedFunction(thread, zone, regexp, cid, /*sticky=*/false, |
| owner); |
| CreateSpecializedFunction(thread, zone, regexp, cid, /*sticky=*/true, |
| owner); |
| } |
| } |
| |
| return regexp.ptr(); |
| } |
| |
| } // namespace dart |