| // 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 "vm/dart_entry.h" |
| #include "vm/regexp_assembler.h" |
| #include "vm/regexp_assembler_bytecode.h" |
| #include "vm/regexp_assembler_ir.h" |
| #include "vm/regexp_ast.h" |
| #include "vm/unibrow-inl.h" |
| #include "vm/unicode.h" |
| #include "vm/symbols.h" |
| #include "vm/thread.h" |
| |
| #define Z (zone()) |
| |
| namespace dart { |
| |
| DECLARE_FLAG(bool, trace_irregexp); |
| DEFINE_FLAG(bool, interpret_irregexp, false, |
| "Use irregexp bytecode interpreter"); |
| |
| // 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 intptr_t* ranges, |
| intptr_t ranges_length, |
| Interval new_range) { |
| ASSERT((ranges_length & 1) == 1); |
| ASSERT(ranges[ranges_length - 1] == Utf16::kMaxCodeUnit + 1); |
| if (containment == kLatticeUnknown) return containment; |
| bool inside = false; |
| intptr_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 ignore_case, |
| bool is_one_byte); |
| |
| intptr_t AllocateRegister() { |
| return next_register_++; |
| } |
| |
| RegExpEngine::CompilationResult Assemble( |
| IRRegExpMacroAssembler* assembler, |
| RegExpNode* start, |
| intptr_t capture_count, |
| const String& pattern); |
| |
| 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 ignore_case() { return ignore_case_; } |
| inline bool one_byte() const { return is_one_byte_; } |
| 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_; |
| ZoneGrowableArray<RegExpNode*>* work_list_; |
| intptr_t recursion_depth_; |
| RegExpMacroAssembler* macro_assembler_; |
| bool ignore_case_; |
| bool is_one_byte_; |
| bool reg_exp_too_big_; |
| 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 ignore_case, |
| bool is_one_byte) |
| : next_register_(2 * (capture_count + 1)), |
| work_list_(NULL), |
| recursion_depth_(0), |
| ignore_case_(ignore_case), |
| is_one_byte_(is_one_byte), |
| reg_exp_too_big_(false), |
| current_expansion_factor_(1), |
| zone_(Thread::Current()->zone()) { |
| accept_ = new(Z) EndNode(EndNode::ACCEPT, Z); |
| } |
| |
| |
| 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_); |
| } |
| |
| |
| 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; |
| intptr_t store_position = -1; |
| // This is a little tricky because we are scanning the actions in reverse |
| // historical order (newest first). |
| for (DeferredAction* action = actions_; |
| action != NULL; |
| action = action->next()) { |
| if (action->Mentions(reg)) { |
| switch (action->action_type()) { |
| case ActionNode::SET_REGISTER: { |
| Trace::DeferredSetRegister* psr = |
| static_cast<Trace::DeferredSetRegister*>(action); |
| if (!absolute) { |
| value += psr->value(); |
| absolute = true; |
| } |
| // SET_REGISTER is currently only used for newly introduced loop |
| // counters. They can have a significant previous value if they |
| // occour in a loop. TODO(lrn): Propagate this information, so we |
| // can set undo_action to ACTION_IGNORE if we know there is no |
| // value to restore. |
| undo_action = ACTION_RESTORE; |
| ASSERT(store_position == -1); |
| ASSERT(!clear); |
| break; |
| } |
| case ActionNode::INCREMENT_REGISTER: |
| if (!absolute) { |
| value++; |
| } |
| ASSERT(store_position == -1); |
| ASSERT(!clear); |
| undo_action = ACTION_RESTORE; |
| break; |
| case ActionNode::STORE_POSITION: { |
| Trace::DeferredCapture* pc = |
| static_cast<Trace::DeferredCapture*>(action); |
| if (!clear && store_position == -1) { |
| store_position = pc->cp_offset(); |
| } |
| |
| // For captures we know that stores and clears alternate. |
| // Other register, are never cleared, and if the occur |
| // inside a loop, they might be assigned more than once. |
| if (reg <= 1) { |
| // Registers zero and one, aka "capture zero", is |
| // always set correctly if we succeed. There is no |
| // need to undo a setting on backtrack, because we |
| // will set it again or fail. |
| undo_action = 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 == -1) { |
| 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 != -1) { |
| assembler->WriteCurrentPositionToRegister(reg, store_position); |
| } else if (clear) { |
| assembler->ClearRegisters(reg, reg); |
| } else if (absolute) { |
| assembler->SetRegister(reg, value); |
| } else if (value != 0) { |
| assembler->AdvanceRegister(reg, value); |
| } |
| } |
| } |
| |
| |
| // This is called as we come into a loop choice node and some other tricky |
| // nodes. It normalizes the state of the code generator to ensure we can |
| // generate generic code. |
| void Trace::Flush(RegExpCompiler* compiler, RegExpNode* successor) { |
| RegExpMacroAssembler* assembler = compiler->macro_assembler(); |
| |
| 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()->IsBound()) { |
| // 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()->IsBound()) { |
| 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, |
| intptr_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, |
| intptr_t first, |
| intptr_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<int>* ranges, |
| intptr_t start_index, |
| intptr_t end_index, |
| intptr_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<int>* 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.IsLinked()); |
| // 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<int>* ranges, |
| intptr_t start_index, |
| intptr_t end_index, |
| intptr_t* new_start_index, |
| intptr_t* new_end_index, |
| intptr_t* border) { |
| static const intptr_t kSize = RegExpMacroAssembler::kTableSize; |
| static const intptr_t kMask = RegExpMacroAssembler::kTableMask; |
| |
| intptr_t first = ranges->At(start_index); |
| intptr_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<int>* 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) { |
| intptr_t first = ranges->At(start_index); |
| intptr_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; |
| intptr_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.IsLinked()) { |
| 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); |
| } |
| |
| intptr_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) { |
| CharacterRange& range = (*ranges)[last_valid_range]; |
| if (range.from() <= max_char) { |
| break; |
| } |
| last_valid_range--; |
| } |
| |
| if (last_valid_range < 0) { |
| if (!cc->is_negated()) { |
| macro_assembler->GoTo(on_failure); |
| } |
| if (check_offset) { |
| macro_assembler->CheckPosition(cp_offset, on_failure); |
| } |
| return; |
| } |
| |
| if (last_valid_range == 0 && |
| ranges->At(0).IsEverything(max_char)) { |
| if (cc->is_negated()) { |
| macro_assembler->GoTo(on_failure); |
| } else { |
| // This is a common case hit by non-anchored expressions. |
| if (check_offset) { |
| macro_assembler->CheckPosition(cp_offset, on_failure); |
| } |
| } |
| return; |
| } |
| if (last_valid_range == 0 && |
| !cc->is_negated() && |
| ranges->At(0).IsEverything(max_char)) { |
| // This is a common case hit by non-anchored expressions. |
| if (check_offset) { |
| macro_assembler->CheckPosition(cp_offset, on_failure); |
| } |
| return; |
| } |
| |
| if (!preloaded) { |
| macro_assembler->LoadCurrentCharacter(cp_offset, on_failure, check_offset); |
| } |
| |
| if (cc->is_standard() && |
| 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<int>* range_boundaries = |
| new(zone) ZoneGrowableArray<int>(last_valid_range); |
| |
| bool zeroth_entry_is_failure = !cc->is_negated(); |
| |
| for (intptr_t i = 0; i <= last_valid_range; i++) { |
| CharacterRange& range = (*ranges)[i]; |
| if (range.from() == 0) { |
| ASSERT(i == 0); |
| zeroth_entry_is_failure = !zeroth_entry_is_failure; |
| } else { |
| range_boundaries->Add(range.from()); |
| } |
| range_boundaries->Add(range.to() + 1); |
| } |
| intptr_t end_index = range_boundaries->length() - 1; |
| if (range_boundaries->At(end_index) > max_char) { |
| end_index--; |
| } |
| |
| 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_.IsBound()) { |
| // 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 (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) { |
| 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 NegativeLookaheadChoiceNode::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 NegativeLookaheadChoiceNode::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 |
| ASSERT(characters_filled_in < details->characters()); |
| intptr_t characters = details->characters(); |
| intptr_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 (compiler->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(); |
| 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) { |
| ASSERT(by >= 0); |
| if (by >= characters_) { |
| 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, bool ignore_case) { |
| if (info()->replacement_calculated) return replacement(); |
| if (depth < 0) return this; |
| ASSERT(!info()->visited); |
| VisitMarker marker(info()); |
| return FilterSuccessor(depth - 1, ignore_case); |
| } |
| |
| |
| RegExpNode* SeqRegExpNode::FilterSuccessor(intptr_t depth, bool ignore_case) { |
| RegExpNode* next = on_success_->FilterOneByte(depth - 1, ignore_case); |
| if (next == NULL) return set_replacement(NULL); |
| on_success_ = next; |
| return set_replacement(this); |
| } |
| |
| |
| // We need to check for the following characters: 0x39c 0x3bc 0x178. |
| static inline bool RangeContainsLatin1Equivalents(CharacterRange range) { |
| // TODO(dcarney): this could be a lot more efficient. |
| return range.Contains(0x39c) || |
| range.Contains(0x3bc) || range.Contains(0x178); |
| } |
| |
| |
| static bool RangesContainLatin1Equivalents( |
| 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, bool ignore_case) { |
| 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 (!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 (ignore_case && 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 (ignore_case && RangesContainLatin1Equivalents(ranges)) continue; |
| return set_replacement(NULL); |
| } |
| } |
| } |
| } |
| return FilterSuccessor(depth - 1, ignore_case); |
| } |
| |
| |
| RegExpNode* LoopChoiceNode::FilterOneByte(intptr_t depth, bool ignore_case) { |
| if (info()->replacement_calculated) return replacement(); |
| if (depth < 0) return this; |
| if (info()->visited) return this; |
| { |
| VisitMarker marker(info()); |
| |
| RegExpNode* continue_replacement = |
| continue_node_->FilterOneByte(depth - 1, ignore_case); |
| // If we can't continue after the loop then there is no sense in doing the |
| // loop. |
| if (continue_replacement == NULL) return set_replacement(NULL); |
| } |
| |
| return ChoiceNode::FilterOneByte(depth - 1, ignore_case); |
| } |
| |
| |
| RegExpNode* ChoiceNode::FilterOneByte(intptr_t depth, bool ignore_case) { |
| 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, ignore_case); |
| 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, ignore_case); |
| if (replacement != NULL) { |
| (*alternatives_)[i].set_node(replacement); |
| new_alternatives->Add((*alternatives_)[i]); |
| } |
| } |
| alternatives_ = new_alternatives; |
| return this; |
| } |
| |
| |
| RegExpNode* NegativeLookaheadChoiceNode::FilterOneByte(intptr_t depth, |
| bool ignore_case) { |
| if (info()->replacement_calculated) return replacement(); |
| if (depth < 0) return this; |
| if (info()->visited) return this; |
| VisitMarker marker(info()); |
| // Alternative 0 is the negative lookahead, alternative 1 is what comes |
| // afterwards. |
| RegExpNode* node = (*alternatives_)[1].node(); |
| RegExpNode* replacement = node->FilterOneByte(depth - 1, ignore_case); |
| 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, ignore_case); |
| // If the negative lookahead is always going to fail then |
| // we don't need to check it. |
| if (neg_replacement == NULL) return set_replacement(replacement); |
| (*alternatives_)[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->backtrack()); |
| Trace at_start_trace = *trace; |
| at_start_trace.set_at_start(true); |
| on_success()->Emit(compiler, &at_start_trace); |
| return; |
| } |
| } |
| break; |
| case AFTER_NEWLINE: |
| EmitHat(compiler, on_success(), trace); |
| return; |
| case AT_BOUNDARY: |
| case AT_NON_BOUNDARY: { |
| EmitBoundaryCheck(compiler, trace); |
| return; |
| } |
| } |
| on_success()->Emit(compiler, trace); |
| } |
| |
| |
| static bool DeterminedAlready(QuickCheckDetails* quick_check, 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(); |
| 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(); |
| 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 (first_element_checked && i == 0 && j == 0) continue; |
| if (DeterminedAlready(quick_check, elm.cp_offset() + j)) continue; |
| EmitCharacterFunction* emit_function = NULL; |
| switch (pass) { |
| case NON_LATIN1_MATCH: |
| ASSERT(one_byte); |
| if (quarks->At(j) > 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) { |
| bool bound_checked = emit_function(Z, |
| compiler, |
| quarks->At(j), |
| backtrack, |
| cp_offset + j, |
| *checked_up_to < cp_offset + j, |
| 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(); |
| EmitCharClass(assembler, |
| cc, |
| one_byte, |
| backtrack, |
| cp_offset, |
| *checked_up_to < cp_offset, |
| 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; |
| } |
| } |
| |
| |
| // 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++) { |
| if (!SkipPass(pass, compiler->ignore_case())) { |
| TextEmitPass(compiler, |
| static_cast<TextEmitPassType>(pass), |
| true, |
| trace, |
| false, |
| &bound_checked_to); |
| } |
| } |
| first_elt_done = true; |
| } |
| |
| for (intptr_t pass = kFirstRealPass; pass <= kLastPass; pass++) { |
| if (!SkipPass(pass, compiler->ignore_case())) { |
| TextEmitPass(compiler, |
| static_cast<TextEmitPassType>(pass), |
| false, |
| trace, |
| first_elt_done, |
| &bound_checked_to); |
| } |
| } |
| |
| Trace successor_trace(*trace); |
| successor_trace.set_at_start(false); |
| successor_trace.AdvanceCurrentPositionInTrace(Length(), compiler); |
| RecursionCheck rc(compiler); |
| on_success()->Emit(compiler, &successor_trace); |
| } |
| |
| |
| void Trace::InvalidateCurrentCharacter() { |
| characters_preloaded_ = 0; |
| } |
| |
| |
| void Trace::AdvanceCurrentPositionInTrace(intptr_t by, |
| RegExpCompiler* compiler) { |
| ASSERT(by > 0); |
| // We don't have an instruction for shifting the current character register |
| // down or for using a shifted value for anything so lets just forget that |
| // we preloaded any characters into it. |
| characters_preloaded_ = 0; |
| // Adjust the offsets of the quick check performed information. This |
| // information is used to find out what we already determined about the |
| // characters by means of mask and compare. |
| quick_check_performed_.Advance(by, compiler->one_byte()); |
| cp_offset_ += by; |
| if (cp_offset_ > RegExpMacroAssembler::kMaxCPOffset) { |
| compiler->SetRegExpTooBig(); |
| cp_offset_ = 0; |
| } |
| bound_checked_up_to_ = 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(); |
| // 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; |
| ZoneGrowableArray<CharacterRange>* ranges = cc->ranges(); |
| intptr_t range_count = ranges->length(); |
| for (intptr_t j = 0; j < range_count; j++) { |
| (*ranges)[j].AddCaseEquivalents(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 (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( |
| 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 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_)[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->macro_assembler()->CanReadUnaligned()) { |
| bool one_byte = compiler->one_byte(); |
| if (one_byte) { |
| if (preload_characters > 4) preload_characters = 4; |
| // We can't preload 3 characters because there is no machine instruction |
| // to do that. We can't just load 4 because we could be reading |
| // beyond the end of the string, which could cause a memory fault. |
| if (preload_characters == 3) preload_characters = 2; |
| } else { |
| if (preload_characters > 2) preload_characters = 2; |
| } |
| } else { |
| if (preload_characters > 1) preload_characters = 1; |
| } |
| return preload_characters; |
| } |
| |
| |
| // This 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( |