| // Copyright 2006-2009 the V8 project authors. All rights reserved. |
| // Redistribution and use in source and binary forms, with or without |
| // modification, are permitted provided that the following conditions are |
| // met: |
| // |
| // * Redistributions of source code must retain the above copyright |
| // notice, this list of conditions and the following disclaimer. |
| // * Redistributions in binary form must reproduce the above |
| // copyright notice, this list of conditions and the following |
| // disclaimer in the documentation and/or other materials provided |
| // with the distribution. |
| // * Neither the name of Google Inc. nor the names of its |
| // contributors may be used to endorse or promote products derived |
| // from this software without specific prior written permission. |
| // |
| // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| |
| #include "v8.h" |
| |
| #include "ast.h" |
| #include "compiler.h" |
| #include "execution.h" |
| #include "factory.h" |
| #include "jsregexp.h" |
| #include "platform.h" |
| #include "string-search.h" |
| #include "runtime.h" |
| #include "top.h" |
| #include "compilation-cache.h" |
| #include "string-stream.h" |
| #include "parser.h" |
| #include "regexp-macro-assembler.h" |
| #include "regexp-macro-assembler-tracer.h" |
| #include "regexp-macro-assembler-irregexp.h" |
| #include "regexp-stack.h" |
| |
| #ifndef V8_INTERPRETED_REGEXP |
| #if V8_TARGET_ARCH_IA32 |
| #include "ia32/regexp-macro-assembler-ia32.h" |
| #elif V8_TARGET_ARCH_X64 |
| #include "x64/regexp-macro-assembler-x64.h" |
| #elif V8_TARGET_ARCH_ARM |
| #include "arm/regexp-macro-assembler-arm.h" |
| #else |
| #error Unsupported target architecture. |
| #endif |
| #endif |
| |
| #include "interpreter-irregexp.h" |
| |
| |
| namespace v8 { |
| namespace internal { |
| |
| |
| Handle<Object> RegExpImpl::CreateRegExpLiteral(Handle<JSFunction> constructor, |
| Handle<String> pattern, |
| Handle<String> flags, |
| bool* has_pending_exception) { |
| // Call the construct code with 2 arguments. |
| Object** argv[2] = { Handle<Object>::cast(pattern).location(), |
| Handle<Object>::cast(flags).location() }; |
| return Execution::New(constructor, 2, argv, has_pending_exception); |
| } |
| |
| |
| static JSRegExp::Flags RegExpFlagsFromString(Handle<String> str) { |
| int flags = JSRegExp::NONE; |
| for (int i = 0; i < str->length(); i++) { |
| switch (str->Get(i)) { |
| case 'i': |
| flags |= JSRegExp::IGNORE_CASE; |
| break; |
| case 'g': |
| flags |= JSRegExp::GLOBAL; |
| break; |
| case 'm': |
| flags |= JSRegExp::MULTILINE; |
| break; |
| } |
| } |
| return JSRegExp::Flags(flags); |
| } |
| |
| |
| static inline void ThrowRegExpException(Handle<JSRegExp> re, |
| Handle<String> pattern, |
| Handle<String> error_text, |
| const char* message) { |
| Handle<JSArray> array = Factory::NewJSArray(2); |
| SetElement(array, 0, pattern); |
| SetElement(array, 1, error_text); |
| Handle<Object> regexp_err = Factory::NewSyntaxError(message, array); |
| Top::Throw(*regexp_err); |
| } |
| |
| |
| // Generic RegExp methods. Dispatches to implementation specific methods. |
| |
| |
| Handle<Object> RegExpImpl::Compile(Handle<JSRegExp> re, |
| Handle<String> pattern, |
| Handle<String> flag_str) { |
| JSRegExp::Flags flags = RegExpFlagsFromString(flag_str); |
| Handle<FixedArray> cached = CompilationCache::LookupRegExp(pattern, flags); |
| bool in_cache = !cached.is_null(); |
| LOG(RegExpCompileEvent(re, in_cache)); |
| |
| Handle<Object> result; |
| if (in_cache) { |
| re->set_data(*cached); |
| return re; |
| } |
| pattern = FlattenGetString(pattern); |
| CompilationZoneScope zone_scope(DELETE_ON_EXIT); |
| PostponeInterruptsScope postpone; |
| RegExpCompileData parse_result; |
| FlatStringReader reader(pattern); |
| if (!RegExpParser::ParseRegExp(&reader, flags.is_multiline(), |
| &parse_result)) { |
| // Throw an exception if we fail to parse the pattern. |
| ThrowRegExpException(re, |
| pattern, |
| parse_result.error, |
| "malformed_regexp"); |
| return Handle<Object>::null(); |
| } |
| |
| if (parse_result.simple && !flags.is_ignore_case()) { |
| // Parse-tree is a single atom that is equal to the pattern. |
| AtomCompile(re, pattern, flags, pattern); |
| } else if (parse_result.tree->IsAtom() && |
| !flags.is_ignore_case() && |
| parse_result.capture_count == 0) { |
| RegExpAtom* atom = parse_result.tree->AsAtom(); |
| Vector<const uc16> atom_pattern = atom->data(); |
| Handle<String> atom_string = Factory::NewStringFromTwoByte(atom_pattern); |
| AtomCompile(re, pattern, flags, atom_string); |
| } else { |
| IrregexpInitialize(re, pattern, flags, parse_result.capture_count); |
| } |
| ASSERT(re->data()->IsFixedArray()); |
| // Compilation succeeded so the data is set on the regexp |
| // and we can store it in the cache. |
| Handle<FixedArray> data(FixedArray::cast(re->data())); |
| CompilationCache::PutRegExp(pattern, flags, data); |
| |
| return re; |
| } |
| |
| |
| Handle<Object> RegExpImpl::Exec(Handle<JSRegExp> regexp, |
| Handle<String> subject, |
| int index, |
| Handle<JSArray> last_match_info) { |
| switch (regexp->TypeTag()) { |
| case JSRegExp::ATOM: |
| return AtomExec(regexp, subject, index, last_match_info); |
| case JSRegExp::IRREGEXP: { |
| Handle<Object> result = |
| IrregexpExec(regexp, subject, index, last_match_info); |
| ASSERT(!result.is_null() || Top::has_pending_exception()); |
| return result; |
| } |
| default: |
| UNREACHABLE(); |
| return Handle<Object>::null(); |
| } |
| } |
| |
| |
| // RegExp Atom implementation: Simple string search using indexOf. |
| |
| |
| void RegExpImpl::AtomCompile(Handle<JSRegExp> re, |
| Handle<String> pattern, |
| JSRegExp::Flags flags, |
| Handle<String> match_pattern) { |
| Factory::SetRegExpAtomData(re, |
| JSRegExp::ATOM, |
| pattern, |
| flags, |
| match_pattern); |
| } |
| |
| |
| static void SetAtomLastCapture(FixedArray* array, |
| String* subject, |
| int from, |
| int to) { |
| NoHandleAllocation no_handles; |
| RegExpImpl::SetLastCaptureCount(array, 2); |
| RegExpImpl::SetLastSubject(array, subject); |
| RegExpImpl::SetLastInput(array, subject); |
| RegExpImpl::SetCapture(array, 0, from); |
| RegExpImpl::SetCapture(array, 1, to); |
| } |
| |
| /* template <typename SubjectChar>, typename PatternChar> |
| static int ReStringMatch(Vector<const SubjectChar> sub_vector, |
| Vector<const PatternChar> pat_vector, |
| int start_index) { |
| |
| int pattern_length = pat_vector.length(); |
| if (pattern_length == 0) return start_index; |
| |
| int subject_length = sub_vector.length(); |
| if (start_index + pattern_length > subject_length) return -1; |
| return SearchString(sub_vector, pat_vector, start_index); |
| } |
| */ |
| Handle<Object> RegExpImpl::AtomExec(Handle<JSRegExp> re, |
| Handle<String> subject, |
| int index, |
| Handle<JSArray> last_match_info) { |
| ASSERT(0 <= index); |
| ASSERT(index <= subject->length()); |
| |
| if (!subject->IsFlat()) FlattenString(subject); |
| AssertNoAllocation no_heap_allocation; // ensure vectors stay valid |
| // Extract flattened substrings of cons strings before determining asciiness. |
| String* seq_sub = *subject; |
| if (seq_sub->IsConsString()) seq_sub = ConsString::cast(seq_sub)->first(); |
| |
| String* needle = String::cast(re->DataAt(JSRegExp::kAtomPatternIndex)); |
| int needle_len = needle->length(); |
| |
| if (needle_len != 0) { |
| if (index + needle_len > subject->length()) return Factory::null_value(); |
| // dispatch on type of strings |
| index = (needle->IsAsciiRepresentation() |
| ? (seq_sub->IsAsciiRepresentation() |
| ? SearchString(seq_sub->ToAsciiVector(), |
| needle->ToAsciiVector(), |
| index) |
| : SearchString(seq_sub->ToUC16Vector(), |
| needle->ToAsciiVector(), |
| index)) |
| : (seq_sub->IsAsciiRepresentation() |
| ? SearchString(seq_sub->ToAsciiVector(), |
| needle->ToUC16Vector(), |
| index) |
| : SearchString(seq_sub->ToUC16Vector(), |
| needle->ToUC16Vector(), |
| index))); |
| if (index == -1) return Factory::null_value(); |
| } |
| ASSERT(last_match_info->HasFastElements()); |
| |
| { |
| NoHandleAllocation no_handles; |
| FixedArray* array = FixedArray::cast(last_match_info->elements()); |
| SetAtomLastCapture(array, *subject, index, index + needle_len); |
| } |
| return last_match_info; |
| } |
| |
| |
| // Irregexp implementation. |
| |
| // Ensures that the regexp object contains a compiled version of the |
| // source for either ASCII or non-ASCII strings. |
| // If the compiled version doesn't already exist, it is compiled |
| // from the source pattern. |
| // If compilation fails, an exception is thrown and this function |
| // returns false. |
| bool RegExpImpl::EnsureCompiledIrregexp(Handle<JSRegExp> re, bool is_ascii) { |
| Object* compiled_code = re->DataAt(JSRegExp::code_index(is_ascii)); |
| #ifdef V8_INTERPRETED_REGEXP |
| if (compiled_code->IsByteArray()) return true; |
| #else // V8_INTERPRETED_REGEXP (RegExp native code) |
| if (compiled_code->IsCode()) return true; |
| #endif |
| return CompileIrregexp(re, is_ascii); |
| } |
| |
| |
| bool RegExpImpl::CompileIrregexp(Handle<JSRegExp> re, bool is_ascii) { |
| // Compile the RegExp. |
| CompilationZoneScope zone_scope(DELETE_ON_EXIT); |
| PostponeInterruptsScope postpone; |
| Object* entry = re->DataAt(JSRegExp::code_index(is_ascii)); |
| if (entry->IsJSObject()) { |
| // If it's a JSObject, a previous compilation failed and threw this object. |
| // Re-throw the object without trying again. |
| Top::Throw(entry); |
| return false; |
| } |
| ASSERT(entry->IsTheHole()); |
| |
| JSRegExp::Flags flags = re->GetFlags(); |
| |
| Handle<String> pattern(re->Pattern()); |
| if (!pattern->IsFlat()) { |
| FlattenString(pattern); |
| } |
| |
| RegExpCompileData compile_data; |
| FlatStringReader reader(pattern); |
| if (!RegExpParser::ParseRegExp(&reader, flags.is_multiline(), |
| &compile_data)) { |
| // Throw an exception if we fail to parse the pattern. |
| // THIS SHOULD NOT HAPPEN. We already pre-parsed it successfully once. |
| ThrowRegExpException(re, |
| pattern, |
| compile_data.error, |
| "malformed_regexp"); |
| return false; |
| } |
| RegExpEngine::CompilationResult result = |
| RegExpEngine::Compile(&compile_data, |
| flags.is_ignore_case(), |
| flags.is_multiline(), |
| pattern, |
| is_ascii); |
| if (result.error_message != NULL) { |
| // Unable to compile regexp. |
| Handle<JSArray> array = Factory::NewJSArray(2); |
| SetElement(array, 0, pattern); |
| SetElement(array, |
| 1, |
| Factory::NewStringFromUtf8(CStrVector(result.error_message))); |
| Handle<Object> regexp_err = |
| Factory::NewSyntaxError("malformed_regexp", array); |
| Top::Throw(*regexp_err); |
| re->SetDataAt(JSRegExp::code_index(is_ascii), *regexp_err); |
| return false; |
| } |
| |
| Handle<FixedArray> data = Handle<FixedArray>(FixedArray::cast(re->data())); |
| data->set(JSRegExp::code_index(is_ascii), result.code); |
| int register_max = IrregexpMaxRegisterCount(*data); |
| if (result.num_registers > register_max) { |
| SetIrregexpMaxRegisterCount(*data, result.num_registers); |
| } |
| |
| return true; |
| } |
| |
| |
| int RegExpImpl::IrregexpMaxRegisterCount(FixedArray* re) { |
| return Smi::cast( |
| re->get(JSRegExp::kIrregexpMaxRegisterCountIndex))->value(); |
| } |
| |
| |
| void RegExpImpl::SetIrregexpMaxRegisterCount(FixedArray* re, int value) { |
| re->set(JSRegExp::kIrregexpMaxRegisterCountIndex, Smi::FromInt(value)); |
| } |
| |
| |
| int RegExpImpl::IrregexpNumberOfCaptures(FixedArray* re) { |
| return Smi::cast(re->get(JSRegExp::kIrregexpCaptureCountIndex))->value(); |
| } |
| |
| |
| int RegExpImpl::IrregexpNumberOfRegisters(FixedArray* re) { |
| return Smi::cast(re->get(JSRegExp::kIrregexpMaxRegisterCountIndex))->value(); |
| } |
| |
| |
| ByteArray* RegExpImpl::IrregexpByteCode(FixedArray* re, bool is_ascii) { |
| return ByteArray::cast(re->get(JSRegExp::code_index(is_ascii))); |
| } |
| |
| |
| Code* RegExpImpl::IrregexpNativeCode(FixedArray* re, bool is_ascii) { |
| return Code::cast(re->get(JSRegExp::code_index(is_ascii))); |
| } |
| |
| |
| void RegExpImpl::IrregexpInitialize(Handle<JSRegExp> re, |
| Handle<String> pattern, |
| JSRegExp::Flags flags, |
| int capture_count) { |
| // Initialize compiled code entries to null. |
| Factory::SetRegExpIrregexpData(re, |
| JSRegExp::IRREGEXP, |
| pattern, |
| flags, |
| capture_count); |
| } |
| |
| |
| int RegExpImpl::IrregexpPrepare(Handle<JSRegExp> regexp, |
| Handle<String> subject) { |
| if (!subject->IsFlat()) { |
| FlattenString(subject); |
| } |
| // Check the asciiness of the underlying storage. |
| bool is_ascii; |
| { |
| AssertNoAllocation no_gc; |
| String* sequential_string = *subject; |
| if (subject->IsConsString()) { |
| sequential_string = ConsString::cast(*subject)->first(); |
| } |
| is_ascii = sequential_string->IsAsciiRepresentation(); |
| } |
| if (!EnsureCompiledIrregexp(regexp, is_ascii)) { |
| return -1; |
| } |
| #ifdef V8_INTERPRETED_REGEXP |
| // Byte-code regexp needs space allocated for all its registers. |
| return IrregexpNumberOfRegisters(FixedArray::cast(regexp->data())); |
| #else // V8_INTERPRETED_REGEXP |
| // Native regexp only needs room to output captures. Registers are handled |
| // internally. |
| return (IrregexpNumberOfCaptures(FixedArray::cast(regexp->data())) + 1) * 2; |
| #endif // V8_INTERPRETED_REGEXP |
| } |
| |
| |
| RegExpImpl::IrregexpResult RegExpImpl::IrregexpExecOnce( |
| Handle<JSRegExp> regexp, |
| Handle<String> subject, |
| int index, |
| Vector<int> output) { |
| Handle<FixedArray> irregexp(FixedArray::cast(regexp->data())); |
| |
| ASSERT(index >= 0); |
| ASSERT(index <= subject->length()); |
| ASSERT(subject->IsFlat()); |
| |
| // A flat ASCII string might have a two-byte first part. |
| if (subject->IsConsString()) { |
| subject = Handle<String>(ConsString::cast(*subject)->first()); |
| } |
| |
| #ifndef V8_INTERPRETED_REGEXP |
| ASSERT(output.length() >= |
| (IrregexpNumberOfCaptures(*irregexp) + 1) * 2); |
| do { |
| bool is_ascii = subject->IsAsciiRepresentation(); |
| Handle<Code> code(IrregexpNativeCode(*irregexp, is_ascii)); |
| NativeRegExpMacroAssembler::Result res = |
| NativeRegExpMacroAssembler::Match(code, |
| subject, |
| output.start(), |
| output.length(), |
| index); |
| if (res != NativeRegExpMacroAssembler::RETRY) { |
| ASSERT(res != NativeRegExpMacroAssembler::EXCEPTION || |
| Top::has_pending_exception()); |
| STATIC_ASSERT( |
| static_cast<int>(NativeRegExpMacroAssembler::SUCCESS) == RE_SUCCESS); |
| STATIC_ASSERT( |
| static_cast<int>(NativeRegExpMacroAssembler::FAILURE) == RE_FAILURE); |
| STATIC_ASSERT(static_cast<int>(NativeRegExpMacroAssembler::EXCEPTION) |
| == RE_EXCEPTION); |
| return static_cast<IrregexpResult>(res); |
| } |
| // If result is RETRY, the string has changed representation, and we |
| // must restart from scratch. |
| // In this case, it means we must make sure we are prepared to handle |
| // the, potentially, different subject (the string can switch between |
| // being internal and external, and even between being ASCII and UC16, |
| // but the characters are always the same). |
| IrregexpPrepare(regexp, subject); |
| } while (true); |
| UNREACHABLE(); |
| return RE_EXCEPTION; |
| #else // V8_INTERPRETED_REGEXP |
| |
| ASSERT(output.length() >= IrregexpNumberOfRegisters(*irregexp)); |
| bool is_ascii = subject->IsAsciiRepresentation(); |
| // We must have done EnsureCompiledIrregexp, so we can get the number of |
| // registers. |
| int* register_vector = output.start(); |
| int number_of_capture_registers = |
| (IrregexpNumberOfCaptures(*irregexp) + 1) * 2; |
| for (int i = number_of_capture_registers - 1; i >= 0; i--) { |
| register_vector[i] = -1; |
| } |
| Handle<ByteArray> byte_codes(IrregexpByteCode(*irregexp, is_ascii)); |
| |
| if (IrregexpInterpreter::Match(byte_codes, |
| subject, |
| register_vector, |
| index)) { |
| return RE_SUCCESS; |
| } |
| return RE_FAILURE; |
| #endif // V8_INTERPRETED_REGEXP |
| } |
| |
| |
| Handle<Object> RegExpImpl::IrregexpExec(Handle<JSRegExp> jsregexp, |
| Handle<String> subject, |
| int previous_index, |
| Handle<JSArray> last_match_info) { |
| ASSERT_EQ(jsregexp->TypeTag(), JSRegExp::IRREGEXP); |
| |
| // Prepare space for the return values. |
| #ifdef V8_INTERPRETED_REGEXP |
| #ifdef DEBUG |
| if (FLAG_trace_regexp_bytecodes) { |
| String* pattern = jsregexp->Pattern(); |
| PrintF("\n\nRegexp match: /%s/\n\n", *(pattern->ToCString())); |
| PrintF("\n\nSubject string: '%s'\n\n", *(subject->ToCString())); |
| } |
| #endif |
| #endif |
| int required_registers = RegExpImpl::IrregexpPrepare(jsregexp, subject); |
| if (required_registers < 0) { |
| // Compiling failed with an exception. |
| ASSERT(Top::has_pending_exception()); |
| return Handle<Object>::null(); |
| } |
| |
| OffsetsVector registers(required_registers); |
| |
| IrregexpResult res = RegExpImpl::IrregexpExecOnce( |
| jsregexp, subject, previous_index, Vector<int>(registers.vector(), |
| registers.length())); |
| if (res == RE_SUCCESS) { |
| int capture_register_count = |
| (IrregexpNumberOfCaptures(FixedArray::cast(jsregexp->data())) + 1) * 2; |
| last_match_info->EnsureSize(capture_register_count + kLastMatchOverhead); |
| AssertNoAllocation no_gc; |
| int* register_vector = registers.vector(); |
| FixedArray* array = FixedArray::cast(last_match_info->elements()); |
| for (int i = 0; i < capture_register_count; i += 2) { |
| SetCapture(array, i, register_vector[i]); |
| SetCapture(array, i + 1, register_vector[i + 1]); |
| } |
| SetLastCaptureCount(array, capture_register_count); |
| SetLastSubject(array, *subject); |
| SetLastInput(array, *subject); |
| return last_match_info; |
| } |
| if (res == RE_EXCEPTION) { |
| ASSERT(Top::has_pending_exception()); |
| return Handle<Object>::null(); |
| } |
| ASSERT(res == RE_FAILURE); |
| return Factory::null_value(); |
| } |
| |
| |
| // ------------------------------------------------------------------- |
| // Implementation of the Irregexp regular expression engine. |
| // |
| // The Irregexp regular expression engine is intended to be a complete |
| // implementation of ECMAScript regular expressions. It generates either |
| // bytecodes or native code. |
| |
| // The Irregexp regexp engine is structured in three steps. |
| // 1) The parser generates an abstract syntax tree. See ast.cc. |
| // 2) From the AST a node network is created. The nodes are all |
| // subclasses of RegExpNode. The nodes represent states when |
| // executing a regular expression. Several optimizations are |
| // performed on the node network. |
| // 3) From the nodes we generate either byte codes or native code |
| // that can actually execute the regular expression (perform |
| // the search). The code generation step is described in more |
| // detail below. |
| |
| // Code generation. |
| // |
| // The nodes are divided into four main categories. |
| // * Choice nodes |
| // These represent places where the regular expression can |
| // match in more than one way. For example on entry to an |
| // alternation (foo|bar) or a repetition (*, +, ? or {}). |
| // * Action nodes |
| // These represent places where some action should be |
| // performed. Examples include recording the current position |
| // in the input string to a register (in order to implement |
| // captures) or other actions on register for example in order |
| // to implement the counters needed for {} repetitions. |
| // * Matching nodes |
| // These attempt to match some element part of the input string. |
| // Examples of elements include character classes, plain strings |
| // or back references. |
| // * End nodes |
| // These are used to implement the actions required on finding |
| // a successful match or failing to find a match. |
| // |
| // The code generated (whether as byte codes or native code) maintains |
| // some state as it runs. This consists of the following elements: |
| // |
| // * The capture registers. Used for string captures. |
| // * Other registers. Used for counters etc. |
| // * The current position. |
| // * The stack of backtracking information. Used when a matching node |
| // fails to find a match and needs to try an alternative. |
| // |
| // Conceptual regular expression execution model: |
| // |
| // There is a simple conceptual model of regular expression execution |
| // which will be presented first. The actual code generated is a more |
| // efficient simulation of the simple conceptual model: |
| // |
| // * Choice nodes are implemented as follows: |
| // For each choice except the last { |
| // push current position |
| // push backtrack code location |
| // <generate code to test for choice> |
| // backtrack code location: |
| // pop current position |
| // } |
| // <generate code to test for last choice> |
| // |
| // * Actions nodes are generated as follows |
| // <push affected registers on backtrack stack> |
| // <generate code to perform action> |
| // push backtrack code location |
| // <generate code to test for following nodes> |
| // backtrack code location: |
| // <pop affected registers to restore their state> |
| // <pop backtrack location from stack and go to it> |
| // |
| // * Matching nodes are generated as follows: |
| // if input string matches at current position |
| // update current position |
| // <generate code to test for following nodes> |
| // else |
| // <pop backtrack location from stack and go to it> |
| // |
| // Thus it can be seen that the current position is saved and restored |
| // by the choice nodes, whereas the registers are saved and restored by |
| // by the action nodes that manipulate them. |
| // |
| // The other interesting aspect of this model is that nodes are generated |
| // at the point where they are needed by a recursive call to Emit(). If |
| // the node has already been code generated then the Emit() call will |
| // generate a jump to the previously generated code instead. In order to |
| // limit recursion it is possible for the Emit() function to put the node |
| // on a work list for later generation and instead generate a jump. The |
| // destination of the jump is resolved later when the code is generated. |
| // |
| // Actual regular expression code generation. |
| // |
| // Code generation is actually more complicated than the above. In order |
| // to improve the efficiency of the generated code some optimizations are |
| // performed |
| // |
| // * Choice nodes have 1-character lookahead. |
| // A choice node looks at the following character and eliminates some of |
| // the choices immediately based on that character. This is not yet |
| // implemented. |
| // * Simple greedy loops store reduced backtracking information. |
| // A quantifier like /.*foo/m will greedily match the whole input. It will |
| // then need to backtrack to a point where it can match "foo". The naive |
| // implementation of this would push each character position onto the |
| // backtracking stack, then pop them off one by one. This would use space |
| // proportional to the length of the input string. However since the "." |
| // can only match in one way and always has a constant length (in this case |
| // of 1) it suffices to store the current position on the top of the stack |
| // once. Matching now becomes merely incrementing the current position and |
| // backtracking becomes decrementing the current position and checking the |
| // result against the stored current position. This is faster and saves |
| // space. |
| // * The current state is virtualized. |
| // This is used to defer expensive operations until it is clear that they |
| // are needed and to generate code for a node more than once, allowing |
| // specialized an efficient versions of the code to be created. This is |
| // explained in the section below. |
| // |
| // Execution state virtualization. |
| // |
| // Instead of emitting code, nodes that manipulate the state can record their |
| // manipulation in an object called the Trace. The Trace object can record a |
| // current position offset, an optional backtrack code location on the top of |
| // the virtualized backtrack stack and some register changes. When a node is |
| // to be emitted it can flush the Trace or update it. Flushing the Trace |
| // will emit code to bring the actual state into line with the virtual state. |
| // Avoiding flushing the state can postpone some work (eg 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 (int i = 0; i < elements()->length(); i++) |
| text->AddElement(elements()->at(i)); |
| } |
| |
| |
| TextElement TextElement::Atom(RegExpAtom* atom) { |
| TextElement result = TextElement(ATOM); |
| result.data.u_atom = atom; |
| return result; |
| } |
| |
| |
| TextElement TextElement::CharClass( |
| RegExpCharacterClass* char_class) { |
| TextElement result = TextElement(CHAR_CLASS); |
| result.data.u_char_class = char_class; |
| return result; |
| } |
| |
| |
| int TextElement::length() { |
| if (type == ATOM) { |
| return data.u_atom->length(); |
| } else { |
| ASSERT(type == CHAR_CLASS); |
| return 1; |
| } |
| } |
| |
| |
| DispatchTable* ChoiceNode::GetTable(bool ignore_case) { |
| if (table_ == NULL) { |
| table_ = new DispatchTable(); |
| DispatchTableConstructor cons(table_, ignore_case); |
| cons.BuildTable(this); |
| } |
| return table_; |
| } |
| |
| |
| class RegExpCompiler { |
| public: |
| RegExpCompiler(int capture_count, bool ignore_case, bool is_ascii); |
| |
| int AllocateRegister() { |
| if (next_register_ >= RegExpMacroAssembler::kMaxRegister) { |
| reg_exp_too_big_ = true; |
| return next_register_; |
| } |
| return next_register_++; |
| } |
| |
| RegExpEngine::CompilationResult Assemble(RegExpMacroAssembler* assembler, |
| RegExpNode* start, |
| int capture_count, |
| Handle<String> pattern); |
| |
| inline void AddWork(RegExpNode* node) { work_list_->Add(node); } |
| |
| static const int kImplementationOffset = 0; |
| static const int kNumberOfRegistersOffset = 0; |
| static const int kCodeOffset = 1; |
| |
| RegExpMacroAssembler* macro_assembler() { return macro_assembler_; } |
| EndNode* accept() { return accept_; } |
| |
| static const int kMaxRecursion = 100; |
| inline int recursion_depth() { return recursion_depth_; } |
| inline void IncrementRecursionDepth() { recursion_depth_++; } |
| inline void DecrementRecursionDepth() { recursion_depth_--; } |
| |
| void SetRegExpTooBig() { reg_exp_too_big_ = true; } |
| |
| inline bool ignore_case() { return ignore_case_; } |
| inline bool ascii() { return ascii_; } |
| |
| static const int kNoRegister = -1; |
| private: |
| EndNode* accept_; |
| int next_register_; |
| List<RegExpNode*>* work_list_; |
| int recursion_depth_; |
| RegExpMacroAssembler* macro_assembler_; |
| bool ignore_case_; |
| bool ascii_; |
| bool reg_exp_too_big_; |
| }; |
| |
| |
| class RecursionCheck { |
| 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(int capture_count, bool ignore_case, bool ascii) |
| : next_register_(2 * (capture_count + 1)), |
| work_list_(NULL), |
| recursion_depth_(0), |
| ignore_case_(ignore_case), |
| ascii_(ascii), |
| reg_exp_too_big_(false) { |
| accept_ = new EndNode(EndNode::ACCEPT); |
| ASSERT(next_register_ - 1 <= RegExpMacroAssembler::kMaxRegister); |
| } |
| |
| |
| RegExpEngine::CompilationResult RegExpCompiler::Assemble( |
| RegExpMacroAssembler* macro_assembler, |
| RegExpNode* start, |
| int capture_count, |
| Handle<String> pattern) { |
| #ifdef DEBUG |
| if (FLAG_trace_regexp_assembler) |
| macro_assembler_ = new RegExpMacroAssemblerTracer(macro_assembler); |
| else |
| #endif |
| macro_assembler_ = macro_assembler; |
| List <RegExpNode*> work_list(0); |
| work_list_ = &work_list; |
| Label fail; |
| macro_assembler_->PushBacktrack(&fail); |
| Trace new_trace; |
| start->Emit(this, &new_trace); |
| macro_assembler_->Bind(&fail); |
| macro_assembler_->Fail(); |
| while (!work_list.is_empty()) { |
| work_list.RemoveLast()->Emit(this, &new_trace); |
| } |
| if (reg_exp_too_big_) return IrregexpRegExpTooBig(); |
| |
| Handle<Object> code = macro_assembler_->GetCode(pattern); |
| |
| work_list_ = NULL; |
| #ifdef DEBUG |
| if (FLAG_trace_regexp_assembler) { |
| delete macro_assembler_; |
| } |
| #endif |
| return RegExpEngine::CompilationResult(*code, next_register_); |
| } |
| |
| |
| bool Trace::DeferredAction::Mentions(int that) { |
| if (type() == ActionNode::CLEAR_CAPTURES) { |
| Interval range = static_cast<DeferredClearCaptures*>(this)->range(); |
| return range.Contains(that); |
| } else { |
| return reg() == that; |
| } |
| } |
| |
| |
| bool Trace::mentions_reg(int reg) { |
| for (DeferredAction* action = actions_; |
| action != NULL; |
| action = action->next()) { |
| if (action->Mentions(reg)) |
| return true; |
| } |
| return false; |
| } |
| |
| |
| bool Trace::GetStoredPosition(int reg, int* cp_offset) { |
| ASSERT_EQ(0, *cp_offset); |
| for (DeferredAction* action = actions_; |
| action != NULL; |
| action = action->next()) { |
| if (action->Mentions(reg)) { |
| if (action->type() == ActionNode::STORE_POSITION) { |
| *cp_offset = static_cast<DeferredCapture*>(action)->cp_offset(); |
| return true; |
| } else { |
| return false; |
| } |
| } |
| } |
| return false; |
| } |
| |
| |
| int Trace::FindAffectedRegisters(OutSet* affected_registers) { |
| int max_register = RegExpCompiler::kNoRegister; |
| for (DeferredAction* action = actions_; |
| action != NULL; |
| action = action->next()) { |
| if (action->type() == ActionNode::CLEAR_CAPTURES) { |
| Interval range = static_cast<DeferredClearCaptures*>(action)->range(); |
| for (int i = range.from(); i <= range.to(); i++) |
| affected_registers->Set(i); |
| if (range.to() > max_register) max_register = range.to(); |
| } else { |
| affected_registers->Set(action->reg()); |
| if (action->reg() > max_register) max_register = action->reg(); |
| } |
| } |
| return max_register; |
| } |
| |
| |
| void Trace::RestoreAffectedRegisters(RegExpMacroAssembler* assembler, |
| int max_register, |
| OutSet& registers_to_pop, |
| OutSet& registers_to_clear) { |
| for (int reg = max_register; reg >= 0; reg--) { |
| if (registers_to_pop.Get(reg)) assembler->PopRegister(reg); |
| else if (registers_to_clear.Get(reg)) { |
| int clear_to = reg; |
| while (reg > 0 && registers_to_clear.Get(reg - 1)) { |
| reg--; |
| } |
| assembler->ClearRegisters(reg, clear_to); |
| } |
| } |
| } |
| |
| |
| void Trace::PerformDeferredActions(RegExpMacroAssembler* assembler, |
| int max_register, |
| OutSet& affected_registers, |
| OutSet* registers_to_pop, |
| OutSet* registers_to_clear) { |
| // The "+1" is to avoid a push_limit of zero if stack_limit_slack() is 1. |
| const int push_limit = (assembler->stack_limit_slack() + 1) / 2; |
| |
| // Count pushes performed to force a stack limit check occasionally. |
| int pushes = 0; |
| |
| for (int reg = 0; reg <= max_register; reg++) { |
| if (!affected_registers.Get(reg)) { |
| continue; |
| } |
| |
| // The chronologically first deferred action in the trace |
| // is used to infer the action needed to restore a register |
| // to its previous state (or not, if it's safe to ignore it). |
| enum DeferredActionUndoType { IGNORE, RESTORE, CLEAR }; |
| DeferredActionUndoType undo_action = IGNORE; |
| |
| int value = 0; |
| bool absolute = false; |
| bool clear = false; |
| int store_position = -1; |
| // This is a little tricky because we are scanning the actions in reverse |
| // historical order (newest first). |
| for (DeferredAction* action = actions_; |
| action != NULL; |
| action = action->next()) { |
| if (action->Mentions(reg)) { |
| switch (action->type()) { |
| case ActionNode::SET_REGISTER: { |
| Trace::DeferredSetRegister* psr = |
| static_cast<Trace::DeferredSetRegister*>(action); |
| if (!absolute) { |
| value += psr->value(); |
| absolute = true; |
| } |
| // SET_REGISTER is currently only used for newly introduced loop |
| // counters. They can have a significant previous value if they |
| // occour in a loop. TODO(lrn): Propagate this information, so |
| // we can set undo_action to IGNORE if we know there is no value to |
| // restore. |
| undo_action = RESTORE; |
| ASSERT_EQ(store_position, -1); |
| ASSERT(!clear); |
| break; |
| } |
| case ActionNode::INCREMENT_REGISTER: |
| if (!absolute) { |
| value++; |
| } |
| ASSERT_EQ(store_position, -1); |
| ASSERT(!clear); |
| undo_action = RESTORE; |
| break; |
| case ActionNode::STORE_POSITION: { |
| Trace::DeferredCapture* pc = |
| static_cast<Trace::DeferredCapture*>(action); |
| if (!clear && store_position == -1) { |
| store_position = pc->cp_offset(); |
| } |
| |
| // For captures we know that stores and clears alternate. |
| // Other register, are never cleared, and if the occur |
| // inside a loop, they might be assigned more than once. |
| if (reg <= 1) { |
| // Registers zero and one, aka "capture zero", is |
| // always set correctly if we succeed. There is no |
| // need to undo a setting on backtrack, because we |
| // will set it again or fail. |
| undo_action = IGNORE; |
| } else { |
| undo_action = pc->is_capture() ? CLEAR : RESTORE; |
| } |
| ASSERT(!absolute); |
| ASSERT_EQ(value, 0); |
| break; |
| } |
| case ActionNode::CLEAR_CAPTURES: { |
| // Since we're scanning in reverse order, if we've already |
| // set the position we have to ignore historically earlier |
| // clearing operations. |
| if (store_position == -1) { |
| clear = true; |
| } |
| undo_action = RESTORE; |
| ASSERT(!absolute); |
| ASSERT_EQ(value, 0); |
| break; |
| } |
| default: |
| UNREACHABLE(); |
| break; |
| } |
| } |
| } |
| // Prepare for the undo-action (e.g., push if it's going to be popped). |
| if (undo_action == RESTORE) { |
| pushes++; |
| RegExpMacroAssembler::StackCheckFlag stack_check = |
| RegExpMacroAssembler::kNoStackLimitCheck; |
| if (pushes == push_limit) { |
| stack_check = RegExpMacroAssembler::kCheckStackLimit; |
| pushes = 0; |
| } |
| |
| assembler->PushRegister(reg, stack_check); |
| registers_to_pop->Set(reg); |
| } else if (undo_action == CLEAR) { |
| registers_to_clear->Set(reg); |
| } |
| // 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(); |
| } |
| |
| int max_register = FindAffectedRegisters(&affected_registers); |
| OutSet registers_to_pop; |
| OutSet registers_to_clear; |
| PerformDeferredActions(assembler, |
| max_register, |
| affected_registers, |
| ®isters_to_pop, |
| ®isters_to_clear); |
| if (cp_offset_ != 0) { |
| assembler->AdvanceCurrentPosition(cp_offset_); |
| } |
| |
| // Create a new trivial state and generate the node with that. |
| Label undo; |
| assembler->PushBacktrack(&undo); |
| Trace new_state; |
| successor->Emit(compiler, &new_state); |
| |
| // On backtrack we need to restore state. |
| assembler->Bind(&undo); |
| RestoreAffectedRegisters(assembler, |
| max_register, |
| registers_to_pop, |
| registers_to_clear); |
| if (backtrack() == NULL) { |
| assembler->Backtrack(); |
| } else { |
| assembler->PopCurrentPosition(); |
| assembler->GoTo(backtrack()); |
| } |
| } |
| |
| |
| void NegativeSubmatchSuccess::Emit(RegExpCompiler* compiler, Trace* trace) { |
| RegExpMacroAssembler* assembler = compiler->macro_assembler(); |
| |
| // Omit flushing the trace. We discard the entire stack frame anyway. |
| |
| if (!label()->is_bound()) { |
| // We are completely independent of the trace, since we ignore it, |
| // so this code can be used as the generic version. |
| assembler->Bind(label()); |
| } |
| |
| // Throw away everything on the backtrack stack since the start |
| // of the negative submatch and restore the character position. |
| assembler->ReadCurrentPositionFromRegister(current_position_register_); |
| assembler->ReadStackPointerFromRegister(stack_pointer_register_); |
| if (clear_capture_count_ > 0) { |
| // Clear any captures that might have been performed during the success |
| // of the body of the negative look-ahead. |
| int clear_capture_end = clear_capture_start_ + clear_capture_count_ - 1; |
| assembler->ClearRegisters(clear_capture_start_, clear_capture_end); |
| } |
| // Now that we have unwound the stack we find at the top of the stack the |
| // backtrack that the BeginSubmatch node got. |
| assembler->Backtrack(); |
| } |
| |
| |
| void EndNode::Emit(RegExpCompiler* compiler, Trace* trace) { |
| if (!trace->is_trivial()) { |
| trace->Flush(compiler, this); |
| return; |
| } |
| RegExpMacroAssembler* assembler = compiler->macro_assembler(); |
| if (!label()->is_bound()) { |
| assembler->Bind(label()); |
| } |
| switch (action_) { |
| case ACCEPT: |
| assembler->Succeed(); |
| return; |
| case BACKTRACK: |
| assembler->GoTo(trace->backtrack()); |
| return; |
| case NEGATIVE_SUBMATCH_SUCCESS: |
| // This case is handled in a different virtual method. |
| UNREACHABLE(); |
| } |
| UNIMPLEMENTED(); |
| } |
| |
| |
| void GuardedAlternative::AddGuard(Guard* guard) { |
| if (guards_ == NULL) |
| guards_ = new ZoneList<Guard*>(1); |
| guards_->Add(guard); |
| } |
| |
| |
| ActionNode* ActionNode::SetRegister(int reg, |
| int val, |
| RegExpNode* on_success) { |
| ActionNode* result = new ActionNode(SET_REGISTER, on_success); |
| result->data_.u_store_register.reg = reg; |
| result->data_.u_store_register.value = val; |
| return result; |
| } |
| |
| |
| ActionNode* ActionNode::IncrementRegister(int reg, RegExpNode* on_success) { |
| ActionNode* result = new ActionNode(INCREMENT_REGISTER, on_success); |
| result->data_.u_increment_register.reg = reg; |
| return result; |
| } |
| |
| |
| ActionNode* ActionNode::StorePosition(int reg, |
| bool is_capture, |
| RegExpNode* on_success) { |
| ActionNode* result = new 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 ActionNode(CLEAR_CAPTURES, on_success); |
| result->data_.u_clear_captures.range_from = range.from(); |
| result->data_.u_clear_captures.range_to = range.to(); |
| return result; |
| } |
| |
| |
| ActionNode* ActionNode::BeginSubmatch(int stack_reg, |
| int position_reg, |
| RegExpNode* on_success) { |
| ActionNode* result = new ActionNode(BEGIN_SUBMATCH, on_success); |
| result->data_.u_submatch.stack_pointer_register = stack_reg; |
| result->data_.u_submatch.current_position_register = position_reg; |
| return result; |
| } |
| |
| |
| ActionNode* ActionNode::PositiveSubmatchSuccess(int stack_reg, |
| int position_reg, |
| int clear_register_count, |
| int clear_register_from, |
| RegExpNode* on_success) { |
| ActionNode* result = new ActionNode(POSITIVE_SUBMATCH_SUCCESS, on_success); |
| result->data_.u_submatch.stack_pointer_register = stack_reg; |
| result->data_.u_submatch.current_position_register = position_reg; |
| result->data_.u_submatch.clear_register_count = clear_register_count; |
| result->data_.u_submatch.clear_register_from = clear_register_from; |
| return result; |
| } |
| |
| |
| ActionNode* ActionNode::EmptyMatchCheck(int start_register, |
| int repetition_register, |
| int repetition_limit, |
| RegExpNode* on_success) { |
| ActionNode* result = new 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; |
| } |
| } |
| |
| |
| static unibrow::Mapping<unibrow::Ecma262UnCanonicalize> uncanonicalize; |
| static unibrow::Mapping<unibrow::CanonicalizationRange> canonrange; |
| |
| |
| // Returns the number of characters in the equivalence class, omitting those |
| // that cannot occur in the source string because it is ASCII. |
| static int GetCaseIndependentLetters(uc16 character, |
| bool ascii_subject, |
| unibrow::uchar* letters) { |
| int length = 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 (!ascii_subject || character <= String::kMaxAsciiCharCode) { |
| return length; |
| } |
| // The standard requires that non-ASCII characters cannot have ASCII |
| // character codes in their equivalence class. |
| return 0; |
| } |
| |
| |
| static inline bool EmitSimpleCharacter(RegExpCompiler* compiler, |
| uc16 c, |
| Label* on_failure, |
| int cp_offset, |
| bool check, |
| bool preloaded) { |
| RegExpMacroAssembler* assembler = compiler->macro_assembler(); |
| bool bound_checked = false; |
| if (!preloaded) { |
| assembler->LoadCurrentCharacter( |
| cp_offset, |
| on_failure, |
| check); |
| bound_checked = true; |
| } |
| assembler->CheckNotCharacter(c, on_failure); |
| return bound_checked; |
| } |
| |
| |
| // Only emits non-letters (things that don't have case). Only used for case |
| // independent matches. |
| static inline bool EmitAtomNonLetter(RegExpCompiler* compiler, |
| uc16 c, |
| Label* on_failure, |
| int cp_offset, |
| bool check, |
| bool preloaded) { |
| RegExpMacroAssembler* macro_assembler = compiler->macro_assembler(); |
| bool ascii = compiler->ascii(); |
| unibrow::uchar chars[unibrow::Ecma262UnCanonicalize::kMaxWidth]; |
| int length = GetCaseIndependentLetters(c, ascii, chars); |
| if (length < 1) { |
| // This can't match. Must be an ASCII subject and a non-ASCII character. |
| // We do not need to do anything since the ASCII 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 (ascii && c > String::kMaxAsciiCharCodeU) { |
| // 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 ascii, |
| uc16 c1, |
| uc16 c2, |
| Label* on_failure) { |
| uc16 char_mask; |
| if (ascii) { |
| char_mask = String::kMaxAsciiCharCode; |
| } else { |
| char_mask = String::kMaxUC16CharCode; |
| } |
| uc16 exor = c1 ^ c2; |
| // Check whether exor has only one bit set. |
| if (((exor - 1) & exor) == 0) { |
| // If c1 and c2 differ only by one bit. |
| // Ecma262UnCanonicalize always gives the highest number last. |
| ASSERT(c2 > c1); |
| uc16 mask = char_mask ^ exor; |
| macro_assembler->CheckNotCharacterAfterAnd(c1, mask, on_failure); |
| return true; |
| } |
| ASSERT(c2 > c1); |
| uc16 diff = c2 - c1; |
| if (((diff - 1) & diff) == 0 && c1 >= diff) { |
| // If the characters differ by 2^n but don't differ by one bit then |
| // subtract the difference from the found character, then do the or |
| // trick. We avoid the theoretical case where negative numbers are |
| // involved in order to simplify code generation. |
| uc16 mask = char_mask ^ diff; |
| macro_assembler->CheckNotCharacterAfterMinusAnd(c1 - diff, |
| diff, |
| mask, |
| on_failure); |
| return true; |
| } |
| return false; |
| } |
| |
| |
| typedef bool EmitCharacterFunction(RegExpCompiler* compiler, |
| uc16 c, |
| Label* on_failure, |
| int cp_offset, |
| bool check, |
| bool preloaded); |
| |
| // Only emits letters (things that have case). Only used for case independent |
| // matches. |
| static inline bool EmitAtomLetter(RegExpCompiler* compiler, |
| uc16 c, |
| Label* on_failure, |
| int cp_offset, |
| bool check, |
| bool preloaded) { |
| RegExpMacroAssembler* macro_assembler = compiler->macro_assembler(); |
| bool ascii = compiler->ascii(); |
| unibrow::uchar chars[unibrow::Ecma262UnCanonicalize::kMaxWidth]; |
| int length = GetCaseIndependentLetters(c, ascii, chars); |
| if (length <= 1) return false; |
| // We may not need to check against the end of the input string |
| // if this character lies before a character that matched. |
| if (!preloaded) { |
| macro_assembler->LoadCurrentCharacter(cp_offset, on_failure, check); |
| } |
| Label ok; |
| ASSERT(unibrow::Ecma262UnCanonicalize::kMaxWidth == 4); |
| switch (length) { |
| case 2: { |
| if (ShortCutEmitCharacterPair(macro_assembler, |
| ascii, |
| chars[0], |
| chars[1], |
| on_failure)) { |
| } else { |
| macro_assembler->CheckCharacter(chars[0], &ok); |
| macro_assembler->CheckNotCharacter(chars[1], on_failure); |
| macro_assembler->Bind(&ok); |
| } |
| break; |
| } |
| case 4: |
| macro_assembler->CheckCharacter(chars[3], &ok); |
| // Fall through! |
| case 3: |
| macro_assembler->CheckCharacter(chars[0], &ok); |
| macro_assembler->CheckCharacter(chars[1], &ok); |
| macro_assembler->CheckNotCharacter(chars[2], on_failure); |
| macro_assembler->Bind(&ok); |
| break; |
| default: |
| UNREACHABLE(); |
| break; |
| } |
| return true; |
| } |
| |
| |
| static void EmitCharClass(RegExpMacroAssembler* macro_assembler, |
| RegExpCharacterClass* cc, |
| bool ascii, |
| Label* on_failure, |
| int cp_offset, |
| bool check_offset, |
| bool preloaded) { |
| ZoneList<CharacterRange>* ranges = cc->ranges(); |
| int max_char; |
| if (ascii) { |
| max_char = String::kMaxAsciiCharCode; |
| } else { |
| max_char = String::kMaxUC16CharCode; |
| } |
| |
| Label success; |
| |
| Label* char_is_in_class = |
| cc->is_negated() ? on_failure : &success; |
| |
| int range_count = ranges->length(); |
| |
| int last_valid_range = range_count - 1; |
| while (last_valid_range >= 0) { |
| CharacterRange& range = ranges->at(last_valid_range); |
| if (range.from() <= max_char) { |
| break; |
| } |
| last_valid_range--; |
| } |
| |
| if (last_valid_range < 0) { |
| if (!cc->is_negated()) { |
| // TODO(plesner): We can remove this when the node level does our |
| // ASCII optimizations for us. |
| macro_assembler->GoTo(on_failure); |
| } |
| 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; |
| } |
| |
| for (int i = 0; i < last_valid_range; i++) { |
| CharacterRange& range = ranges->at(i); |
| Label next_range; |
| uc16 from = range.from(); |
| uc16 to = range.to(); |
| if (from > max_char) { |
| continue; |
| } |
| if (to > max_char) to = max_char; |
| if (to == from) { |
| macro_assembler->CheckCharacter(to, char_is_in_class); |
| } else { |
| if (from != 0) { |
| macro_assembler->CheckCharacterLT(from, &next_range); |
| } |
| if (to != max_char) { |
| macro_assembler->CheckCharacterLT(to + 1, char_is_in_class); |
| } else { |
| macro_assembler->GoTo(char_is_in_class); |
| } |
| } |
| macro_assembler->Bind(&next_range); |
| } |
| |
| CharacterRange& range = ranges->at(last_valid_range); |
| uc16 from = range.from(); |
| uc16 to = range.to(); |
| |
| if (to > max_char) to = max_char; |
| ASSERT(to >= from); |
| |
| if (to == from) { |
| if (cc->is_negated()) { |
| macro_assembler->CheckCharacter(to, on_failure); |
| } else { |
| macro_assembler->CheckNotCharacter(to, on_failure); |
| } |
| } else { |
| if (from != 0) { |
| if (cc->is_negated()) { |
| macro_assembler->CheckCharacterLT(from, &success); |
| } else { |
| macro_assembler->CheckCharacterLT(from, on_failure); |
| } |
| } |
| if (to != String::kMaxUC16CharCode) { |
| if (cc->is_negated()) { |
| macro_assembler->CheckCharacterLT(to + 1, on_failure); |
| } else { |
| macro_assembler->CheckCharacterGT(to, on_failure); |
| } |
| } else { |
| if (cc->is_negated()) { |
| macro_assembler->GoTo(on_failure); |
| } |
| } |
| } |
| macro_assembler->Bind(&success); |
| } |
| |
| |
| RegExpNode::~RegExpNode() { |
| } |
| |
| |
| RegExpNode::LimitResult RegExpNode::LimitVersions(RegExpCompiler* compiler, |
| Trace* trace) { |
| // If we are generating a greedy loop then don't stop and don't reuse code. |
| if (trace->stop_node() != NULL) { |
| return CONTINUE; |
| } |
| |
| RegExpMacroAssembler* macro_assembler = compiler->macro_assembler(); |
| if (trace->is_trivial()) { |
| if (label_.is_bound()) { |
| // We are being asked to generate a generic version, but that's already |
| // been done so just go to it. |
| macro_assembler->GoTo(&label_); |
| return DONE; |
| } |
| if (compiler->recursion_depth() >= RegExpCompiler::kMaxRecursion) { |
| // To avoid too deep recursion we push the node to the work queue and just |
| // generate a goto here. |
| compiler->AddWork(this); |
| macro_assembler->GoTo(&label_); |
| return DONE; |
| } |
| // Generate generic version of the node and bind the label for later use. |
| macro_assembler->Bind(&label_); |
| return CONTINUE; |
| } |
| |
| // We are being asked to make a non-generic version. Keep track of how many |
| // non-generic versions we generate so as not to overdo it. |
| trace_count_++; |
| if (FLAG_regexp_optimization && |
| trace_count_ < kMaxCopiesCodeGenerated && |
| compiler->recursion_depth() <= RegExpCompiler::kMaxRecursion) { |
| return CONTINUE; |
| } |
| |
| // If we get here code has been generated for this node too many times or |
| // recursion is too deep. Time to switch to a generic version. The code for |
| // generic versions above can handle deep recursion properly. |
| trace->Flush(compiler, this); |
| return DONE; |
| } |
| |
| |
| int ActionNode::EatsAtLeast(int still_to_find, |
| int recursion_depth, |
| bool not_at_start) { |
| if (recursion_depth > RegExpCompiler::kMaxRecursion) return 0; |
| if (type_ == POSITIVE_SUBMATCH_SUCCESS) return 0; // Rewinds input! |
| return on_success()->EatsAtLeast(still_to_find, |
| recursion_depth + 1, |
| not_at_start); |
| } |
| |
| |
| int AssertionNode::EatsAtLeast(int still_to_find, |
| int recursion_depth, |
| bool not_at_start) { |
| if (recursion_depth > RegExpCompiler::kMaxRecursion) 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 (type() == AT_START && not_at_start) return still_to_find; |
| return on_success()->EatsAtLeast(still_to_find, |
| recursion_depth + 1, |
| not_at_start); |
| } |
| |
| |
| int BackReferenceNode::EatsAtLeast(int still_to_find, |
| int recursion_depth, |
| bool not_at_start) { |
| if (recursion_depth > RegExpCompiler::kMaxRecursion) return 0; |
| return on_success()->EatsAtLeast(still_to_find, |
| recursion_depth + 1, |
| not_at_start); |
| } |
| |
| |
| int TextNode::EatsAtLeast(int still_to_find, |
| int recursion_depth, |
| bool not_at_start) { |
| int answer = Length(); |
| if (answer >= still_to_find) return answer; |
| if (recursion_depth > RegExpCompiler::kMaxRecursion) 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, |
| recursion_depth + 1, |
| true); |
| } |
| |
| |
| int NegativeLookaheadChoiceNode::EatsAtLeast(int still_to_find, |
| int recursion_depth, |
| bool not_at_start) { |
| if (recursion_depth > RegExpCompiler::kMaxRecursion) return 0; |
| // Alternative 0 is the negative lookahead, alternative 1 is what comes |
| // afterwards. |
| RegExpNode* node = alternatives_->at(1).node(); |
| return node->EatsAtLeast(still_to_find, recursion_depth + 1, not_at_start); |
| } |
| |
| |
| void NegativeLookaheadChoiceNode::GetQuickCheckDetails( |
| QuickCheckDetails* details, |
| RegExpCompiler* compiler, |
| int filled_in, |
| bool not_at_start) { |
| // Alternative 0 is the negative lookahead, alternative 1 is what comes |
| // afterwards. |
| RegExpNode* node = alternatives_->at(1).node(); |
| return node->GetQuickCheckDetails(details, compiler, filled_in, not_at_start); |
| } |
| |
| |
| int ChoiceNode::EatsAtLeastHelper(int still_to_find, |
| int recursion_depth, |
| RegExpNode* ignore_this_node, |
| bool not_at_start) { |
| if (recursion_depth > RegExpCompiler::kMaxRecursion) return 0; |
| int min = 100; |
| int choice_count = alternatives_->length(); |
| for (int i = 0; i < choice_count; i++) { |
| RegExpNode* node = alternatives_->at(i).node(); |
| if (node == ignore_this_node) continue; |
| int node_eats_at_least = node->EatsAtLeast(still_to_find, |
| recursion_depth + 1, |
| not_at_start); |
| if (node_eats_at_least < min) min = node_eats_at_least; |
| } |
| return min; |
| } |
| |
| |
| int LoopChoiceNode::EatsAtLeast(int still_to_find, |
| int recursion_depth, |
| bool not_at_start) { |
| return EatsAtLeastHelper(still_to_find, |
| recursion_depth, |
| loop_node_, |
| not_at_start); |
| } |
| |
| |
| int ChoiceNode::EatsAtLeast(int still_to_find, |
| int recursion_depth, |
| bool not_at_start) { |
| return EatsAtLeastHelper(still_to_find, |
| recursion_depth, |
| NULL, |
| not_at_start); |
| } |
| |
| |
| // Takes the left-most 1-bit and smears it out, setting all bits to its right. |
| static inline uint32_t SmearBitsRight(uint32_t v) { |
| v |= v >> 1; |
| v |= v >> 2; |
| v |= v >> 4; |
| v |= v >> 8; |
| v |= v >> 16; |
| return v; |
| } |
| |
| |
| bool QuickCheckDetails::Rationalize(bool asc) { |
| bool found_useful_op = false; |
| uint32_t char_mask; |
| if (asc) { |
| char_mask = String::kMaxAsciiCharCode; |
| } else { |
| char_mask = String::kMaxUC16CharCode; |
| } |
| mask_ = 0; |
| value_ = 0; |
| int char_shift = 0; |
| for (int i = 0; i < characters_; i++) { |
| Position* pos = &positions_[i]; |
| if ((pos->mask & String::kMaxAsciiCharCode) != 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* trace, |
| bool preload_has_checked_bounds, |
| Label* on_possible_success, |
| QuickCheckDetails* details, |
| bool fall_through_on_failure) { |
| if (details->characters() == 0) return false; |
| GetQuickCheckDetails(details, compiler, 0, trace->at_start() == Trace::FALSE); |
| if (details->cannot_match()) return false; |
| if (!details->Rationalize(compiler->ascii())) 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()) { |
| assembler->LoadCurrentCharacter(trace->cp_offset(), |
| 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->ascii()) { |
| char_mask = String::kMaxAsciiCharCode; |
| } else { |
| char_mask = String::kMaxUC16CharCode; |
| } |
| if ((mask & char_mask) == char_mask) need_mask = false; |
| mask &= char_mask; |
| } else { |
| // For 2-character preloads in ASCII mode or 1-character preloads in |
| // TWO_BYTE mode we also use a 16 bit load with zero extend. |
| if (details->characters() == 2 && compiler->ascii()) { |
| if ((mask & 0x7f7f) == 0x7f7f) need_mask = false; |
| } else if (details->characters() == 1 && !compiler->ascii()) { |
| if ((mask & 0xffff) == 0xffff) need_mask = false; |
| } else { |
| if (mask == 0xffffffff) need_mask = false; |
| } |
| } |
| |
| if (fall_through_on_failure) { |
| if (need_mask) { |
| assembler->CheckCharacterAfterAnd(value, mask, on_possible_success); |
| } else { |
| assembler->CheckCharacter(value, on_possible_success); |
| } |
| } else { |
| if (need_mask) { |
| assembler->CheckNotCharacterAfterAnd(value, mask, trace->backtrack()); |
| } else { |
| assembler->CheckNotCharacter(value, trace->backtrack()); |
| } |
| } |
| return true; |
| } |
| |
| |
| // Here is the meat of GetQuickCheckDetails (see also the comment on the |
| // super-class in the .h file). |
| // |
| // We iterate along the text object, building up for each character a |
| // mask and value that can be used to test for a quick failure to match. |
| // The masks and values for the positions will be combined into a single |
| // machine word for the current character width in order to be used in |
| // generating a quick check. |
| void TextNode::GetQuickCheckDetails(QuickCheckDetails* details, |
| RegExpCompiler* compiler, |
| int characters_filled_in, |
| bool not_at_start) { |
| ASSERT(characters_filled_in < details->characters()); |
| int characters = details->characters(); |
| int char_mask; |
| int char_shift; |
| if (compiler->ascii()) { |
| char_mask = String::kMaxAsciiCharCode; |
| char_shift = 8; |
| } else { |
| char_mask = String::kMaxUC16CharCode; |
| char_shift = 16; |
| } |
| for (int k = 0; k < elms_->length(); k++) { |
| TextElement elm = elms_->at(k); |
| if (elm.type == TextElement::ATOM) { |
| Vector<const uc16> quarks = elm.data.u_atom->data(); |
| for (int i = 0; i < characters && i < quarks.length(); i++) { |
| QuickCheckDetails::Position* pos = |
| details->positions(characters_filled_in); |
| uc16 c = quarks[i]; |
| if (c > char_mask) { |
| // If we expect a non-ASCII character from an ASCII string, |
| // there is no way we can match. Not even case independent |
| // matching can turn an ASCII character into non-ASCII or |
| // vice versa. |
| details->set_cannot_match(); |
| pos->determines_perfectly = false; |
| return; |
| } |
| if (compiler->ignore_case()) { |
| unibrow::uchar chars[unibrow::Ecma262UnCanonicalize::kMaxWidth]; |
| int length = GetCaseIndependentLetters(c, compiler->ascii(), 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 (int j = 1; j < length; j++) { |
| uint32_t differing_bits = ((chars[j] & common_bits) ^ bits); |
| common_bits ^= differing_bits; |
| bits &= common_bits; |
| } |
| // If length is 2 and common bits has only one zero in it then |
| // our mask and compare instruction will determine definitely |
| // whether we have a match at this character position. Otherwise |
| // it can only be an approximate check. |
| uint32_t one_zero = (common_bits | ~char_mask); |
| if (length == 2 && ((~one_zero) & ((~one_zero) - 1)) == 0) { |
| pos->determines_perfectly = true; |
| } |
| pos->mask = common_bits; |
| pos->value = bits; |
| } |
| } else { |
| // Don't ignore case. Nice simple case where the mask-compare will |
| // determine definitely whether we have a match at this character |
| // position. |
| pos->mask = char_mask; |
| pos->value = c; |
| pos->determines_perfectly = true; |
| } |
| characters_filled_in++; |
| 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.data.u_char_class; |
| ZoneList<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 { |
| int first_range = 0; |
| while (ranges->at(first_range).from() > char_mask) { |
| first_range++; |
| if (first_range == ranges->length()) { |
| details->set_cannot_match(); |
| pos->determines_perfectly = false; |
| return; |
| } |
| } |
| CharacterRange range = ranges->at(first_range); |
| uc16 from = range.from(); |
| uc16 to = range.to(); |
| if (to > char_mask) { |
| to = char_mask; |
| } |
| uint32_t differing_bits = (from ^ to); |
| // A mask and compare is only perfect if the differing bits form a |
| // number like 00011111 with one single block of trailing 1s. |
| if ((differing_bits & (differing_bits + 1)) == 0 && |
| from + differing_bits == to) { |
| pos->determines_perfectly = true; |
| } |
| uint32_t common_bits = ~SmearBitsRight(differing_bits); |
| uint32_t bits = (from & common_bits); |
| for (int i = first_range + 1; i < ranges->length(); i++) { |
| CharacterRange range = ranges->at(i); |
| uc16 from = range.from(); |
| uc16 to = range.to(); |
| if (from > char_mask) continue; |
| if (to > char_mask) to = char_mask; |
| // Here we are combining more ranges into the mask and compare |
| // value. With each new range the mask becomes more sparse and |
| // so the chances of a false positive rise. A character class |
| // with multiple ranges is assumed never to be equivalent to a |
| // mask and compare operation. |
| pos->determines_perfectly = false; |
| uint32_t new_common_bits = (from ^ to); |
| new_common_bits = ~SmearBitsRight(new_common_bits); |
| common_bits &= new_common_bits; |
| bits &= new_common_bits; |
| uint32_t differing_bits = (from & common_bits) ^ bits; |
| common_bits ^= differing_bits; |
| bits &= common_bits; |
| } |
| pos->mask = common_bits; |
| pos->value = bits; |
| } |
| characters_filled_in++; |
| ASSERT(characters_filled_in <= details->characters()); |
| if (characters_filled_in == details->characters()) { |
| return; |
| } |
| } |
| } |
| ASSERT(characters_filled_in != details->characters()); |
| on_success()-> GetQuickCheckDetails(details, |
| compiler, |
| characters_filled_in, |
| true); |
| } |
| |
| |
| void QuickCheckDetails::Clear() { |
| for (int i = 0; i < characters_; i++) { |
| positions_[i].mask = 0; |
| positions_[i].value = 0; |
| positions_[i].determines_perfectly = false; |
| } |
| characters_ = 0; |
| } |
| |
| |
| void QuickCheckDetails::Advance(int by, bool ascii) { |
| ASSERT(by >= 0); |
| if (by >= characters_) { |
| Clear(); |
| return; |
| } |
| for (int i = 0; i < characters_ - by; i++) { |
| positions_[i] = positions_[by + i]; |
| } |
| for (int i = characters_ - by; i < characters_; i++) { |
| positions_[i].mask = 0; |
| positions_[i].value = 0; |
| positions_[i].determines_perfectly = false; |
| } |
| characters_ -= by; |
| // We could change mask_ and value_ here but we would never advance unless |
| // they had already been used in a check and they won't be used again because |
| // it would gain us nothing. So there's no point. |
| } |
| |
| |
| void QuickCheckDetails::Merge(QuickCheckDetails* other, int from_index) { |
| ASSERT(characters_ == other->characters_); |
| if (other->cannot_match_) { |
| return; |
| } |
| if (cannot_match_) { |
| *this = *other; |
| return; |
| } |
| for (int i = from_index; i < characters_; i++) { |
| QuickCheckDetails::Position* pos = positions(i); |
| QuickCheckDetails::Position* other_pos = other->positions(i); |
| if (pos->mask != other_pos->mask || |
| pos->value != other_pos->value || |
| !other_pos->determines_perfectly) { |
| // Our mask-compare operation will be approximate unless we have the |
| // exact same operation on both sides of the alternation. |
| pos->determines_perfectly = false; |
| } |
| pos->mask &= other_pos->mask; |
| pos->value &= pos->mask; |
| other_pos->value &= pos->mask; |
| uc16 differing_bits = (pos->value ^ other_pos->value); |
| pos->mask &= ~differing_bits; |
| pos->value &= pos->mask; |
| } |
| } |
| |
| |
| class VisitMarker { |
| public: |
| explicit VisitMarker(NodeInfo* info) : info_(info) { |
| ASSERT(!info->visited); |
| info->visited = true; |
| } |
| ~VisitMarker() { |
| info_->visited = false; |
| } |
| private: |
| NodeInfo* info_; |
| }; |
| |
| |
| void LoopChoiceNode::GetQuickCheckDetails(QuickCheckDetails* details, |
| RegExpCompiler* compiler, |
| int characters_filled_in, |
| bool not_at_start) { |
| if (body_can_be_zero_length_ || info()->visited) return; |
| VisitMarker marker(info()); |
| return ChoiceNode::GetQuickCheckDetails(details, |
| compiler, |
| characters_filled_in, |
| not_at_start); |
| } |
| |
| |
| void ChoiceNode::GetQuickCheckDetails(QuickCheckDetails* details, |
| RegExpCompiler* compiler, |
| int characters_filled_in, |
| bool not_at_start) { |
| not_at_start = (not_at_start || not_at_start_); |
| int choice_count = alternatives_->length(); |
| ASSERT(choice_count > 0); |
| alternatives_->at(0).node()->GetQuickCheckDetails(details, |
| compiler, |
| characters_filled_in, |
| not_at_start); |
| for (int i = 1; i < choice_count; i++) { |
| QuickCheckDetails new_details(details->characters()); |
| RegExpNode* node = alternatives_->at(i).node(); |
| node->GetQuickCheckDetails(&new_details, compiler, |
| characters_filled_in, |
| not_at_start); |
| // Here we merge the quick match details of the two branches. |
| details->Merge(&new_details, characters_filled_in); |
| } |
| } |
| |
| |
| // Check for [0-9A-Z_a-z]. |
| static void EmitWordCheck(RegExpMacroAssembler* assembler, |
| Label* word, |
| Label* non_word, |
| bool fall_through_on_word) { |
| if (assembler->CheckSpecialCharacterClass( |
| fall_through_on_word ? 'w' : 'W', |
| fall_through_on_word ? non_word : word)) { |
| // Optimized implementation available. |
| return; |
| } |
| assembler->CheckCharacterGT('z', non_word); |
| assembler->CheckCharacterLT('0', non_word); |
| assembler->CheckCharacterGT('a' - 1, word); |
| assembler->CheckCharacterLT('9' + 1, word); |
| assembler->CheckCharacterLT('A', non_word); |
| assembler->CheckCharacterLT('Z' + 1, word); |
| if (fall_through_on_word) { |
| assembler->CheckNotCharacter('_', non_word); |
| } else { |
| assembler->CheckCharacter('_', word); |
| } |
| } |
| |
| |
| // Emit the code to check for a ^ in multiline mode (1-character lookbehind |
| // that matches newline or the start of input). |
| static void EmitHat(RegExpCompiler* compiler, |
| RegExpNode* on_success, |
| Trace* trace) { |
| RegExpMacroAssembler* assembler = compiler->macro_assembler(); |
| // We will be loading the previous character into the current character |
| // register. |
| Trace new_trace(*trace); |
| new_trace.InvalidateCurrentCharacter(); |
| |
| Label ok; |
| if (new_trace.cp_offset() == 0) { |
| // The start of input counts as a newline in this context, so skip to |
| // ok if we are at the start. |
| assembler->CheckAtStart(&ok); |
| } |
| // We already checked that we are not at the start of input so it must be |
| // OK to load the previous character. |
| assembler->LoadCurrentCharacter(new_trace.cp_offset() -1, |
| new_trace.backtrack(), |
| false); |
| if (!assembler->CheckSpecialCharacterClass('n', |
| new_trace.backtrack())) { |
| // Newline means \n, \r, 0x2028 or 0x2029. |
| if (!compiler->ascii()) { |
| assembler->CheckCharacterAfterAnd(0x2028, 0xfffe, &ok); |
| } |
| assembler->CheckCharacter('\n', &ok); |
| assembler->CheckNotCharacter('\r', new_trace.backtrack()); |
| } |
| assembler->Bind(&ok); |
| on_success->Emit(compiler, &new_trace); |
| } |
| |
| |
| // Emit the code to handle \b and \B (word-boundary or non-word-boundary) |
| // when we know whether the next character must be a word character or not. |
| static void EmitHalfBoundaryCheck(AssertionNode::AssertionNodeType type, |
| RegExpCompiler* compiler, |
| RegExpNode* on_success, |
| Trace* trace) { |
| RegExpMacroAssembler* assembler = compiler->macro_assembler(); |
| Label done; |
| |
| Trace new_trace(*trace); |
| |
| bool expect_word_character = (type == AssertionNode::AFTER_WORD_CHARACTER); |
| Label* on_word = expect_word_character ? &done : new_trace.backtrack(); |
| Label* on_non_word = expect_word_character ? new_trace.backtrack() : &done; |
| |
| // Check whether previous character was a word character. |
| switch (trace->at_start()) { |
| case Trace::TRUE: |
| if (expect_word_character) { |
| assembler->GoTo(on_non_word); |
| } |
| break; |
| case Trace::UNKNOWN: |
| ASSERT_EQ(0, trace->cp_offset()); |
| assembler->CheckAtStart(on_non_word); |
| // Fall through. |
| case Trace::FALSE: |
| int prev_char_offset = trace->cp_offset() - 1; |
| assembler->LoadCurrentCharacter(prev_char_offset, NULL, false, 1); |
| EmitWordCheck(assembler, on_word, on_non_word, expect_word_character); |
| // We may or may not have loaded the previous character. |
| new_trace.InvalidateCurrentCharacter(); |
| } |
| |
| assembler->Bind(&done); |
| |
| on_success->Emit(compiler, &new_trace); |
| } |
| |
| |
| // Emit the code to handle \b and \B (word-boundary or non-word-boundary). |
| static void EmitBoundaryCheck(AssertionNode::AssertionNodeType type, |
| RegExpCompiler* compiler, |
| RegExpNode* on_success, |
| Trace* trace) { |
| RegExpMacroAssembler* assembler = compiler->macro_assembler(); |
| Label before_non_word; |
| Label before_word; |
| if (trace->characters_preloaded() != 1) { |
| assembler->LoadCurrentCharacter(trace->cp_offset(), &before_non_word); |
| } |
| // Fall through on non-word. |
| EmitWordCheck(assembler, &before_word, &before_non_word, false); |
| |
| // We will be loading the previous character into the current character |
| // register. |
| Trace new_trace(*trace); |
| new_trace.InvalidateCurrentCharacter(); |
| |
| Label ok; |
| Label* boundary; |
| Label* not_boundary; |
| if (type == AssertionNode::AT_BOUNDARY) { |
| boundary = &ok; |
| not_boundary = new_trace.backtrack(); |
| } else { |
| not_boundary = &ok; |
| boundary = new_trace.backtrack(); |
| } |
| |
| // Next character is not a word character. |
| assembler->Bind(&before_non_word); |
| 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(not_boundary); |
| } |
| // 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, |
| &ok, // Unused dummy label in this call. |
| false); |
| // Fall through on non-word. |
| EmitWordCheck(assembler, boundary, not_boundary, false); |
| assembler->GoTo(not_boundary); |
| |
| // Next character is a word character. |
| assembler->Bind(&before_word); |
| 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(boundary); |
| } |
| // 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, |
| &ok, // Unused dummy label in this call. |
| false); |
| bool fall_through_on_word = (type == AssertionNode::AT_NON_BOUNDARY); |
| EmitWordCheck(assembler, not_boundary, boundary, fall_through_on_word); |
| |
| assembler->Bind(&ok); |
| |
| on_success->Emit(compiler, &new_trace); |
| } |
| |
| |
| void AssertionNode::GetQuickCheckDetails(QuickCheckDetails* details, |
| RegExpCompiler* compiler, |
| int filled_in, |
| bool not_at_start) { |
| if (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 (type_) { |
| case AT_END: { |
| Label ok; |
| assembler->CheckPosition(trace->cp_offset(), &ok); |
| assembler->GoTo(trace->backtrack()); |
| assembler->Bind(&ok); |
| break; |
| } |
| case AT_START: { |
| if (trace->at_start() == Trace::FALSE) { |
| 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(type_, compiler, on_success(), trace); |
| return; |
| } |
| case AFTER_WORD_CHARACTER: |
| case AFTER_NONWORD_CHARACTER: { |
| EmitHalfBoundaryCheck(type_, compiler, on_success(), trace); |
| } |
| } |
| on_success()->Emit(compiler, trace); |
| } |
| |
| |
| static bool DeterminedAlready(QuickCheckDetails* quick_check, int offset) { |
| if (quick_check == NULL) return false; |
| if (offset >= quick_check->characters()) return false; |
| return quick_check->positions(offset)->determines_perfectly; |
| } |
| |
| |
| static void UpdateBoundsCheck(int index, int* checked_up_to) { |
| if (index > *checked_up_to) { |
| *checked_up_to = index; |
| } |
| } |
| |
| |
| // We call this repeatedly to generate code for each pass over the text node. |
| // The passes are in increasing order of difficulty because we hope one |
| // of the first passes will fail in which case we are saved the work of the |
| // later passes. for example for the case independent regexp /%[asdfghjkl]a/ |
| // we will check the '%' in the first pass, the case independent 'a' in the |
| // second pass and the character class in the last pass. |
| // |
| // The passes are done from right to left, so for example to test for /bar/ |
| // we will first test for an 'r' with offset 2, then an 'a' with offset 1 |
| // and then a 'b' with offset 0. This means we can avoid the end-of-input |
| // bounds check most of the time. In the example we only need to check for |
| // end-of-input when loading the putative 'r'. |
| // |
| // A slight complication involves the fact that the first character may already |
| // be fetched into a register by the previous node. In this case we want to |
| // do the test for that character first. We do this in separate passes. The |
| // 'preloaded' argument indicates that we are doing such a 'pass'. If such a |
| // pass has been performed then subsequent passes will have true in |
| // first_element_checked to indicate that that character does not need to be |
| // checked again. |
| // |
| // In addition to all this we are passed a Trace, which can |
| // contain an AlternativeGeneration object. In this AlternativeGeneration |
| // object we can see details of any quick check that was already passed in |
| // order to get to the code we are now generating. The quick check can involve |
| // loading characters, which means we do not need to recheck the bounds |
| // up to the limit the quick check already checked. In addition the quick |
| // check can have involved a mask and compare operation which may simplify |
| // or obviate the need for further checks at some character positions. |
| void TextNode::TextEmitPass(RegExpCompiler* compiler, |
| TextEmitPassType pass, |
| bool preloaded, |
| Trace* trace, |
| bool first_element_checked, |
| int* checked_up_to) { |
| RegExpMacroAssembler* assembler = compiler->macro_assembler(); |
| bool ascii = compiler->ascii(); |
| Label* backtrack = trace->backtrack(); |
| QuickCheckDetails* quick_check = trace->quick_check_performed(); |
| int element_count = elms_->length(); |
| for (int i = preloaded ? 0 : element_count - 1; i >= 0; i--) { |
| TextElement elm = elms_->at(i); |
| int cp_offset = trace->cp_offset() + elm.cp_offset; |
| if (elm.type == TextElement::ATOM) { |
| Vector<const uc16> quarks = elm.data.u_atom->data(); |
| for (int j = preloaded ? 0 : quarks.length() - 1; j >= 0; j--) { |
| if (first_element_checked && i == 0 && j == 0) continue; |
| if (DeterminedAlready(quick_check, elm.cp_offset + j)) continue; |
| EmitCharacterFunction* emit_function = NULL; |
| switch (pass) { |
| case NON_ASCII_MATCH: |
| ASSERT(ascii); |
| if (quarks[j] > String::kMaxAsciiCharCode) { |
| 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(compiler, |
| quarks[j], |
| backtrack, |
| cp_offset + j, |
| *checked_up_to < cp_offset + j, |
| preloaded); |
| if (bound_checked) UpdateBoundsCheck(cp_offset + j, checked_up_to); |
| } |
| } |
| } else { |
| ASSERT_EQ(elm.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.data.u_char_class; |
| EmitCharClass(assembler, |
| cc, |
| ascii, |
| backtrack, |
| cp_offset, |
| *checked_up_to < cp_offset, |
| preloaded); |
| UpdateBoundsCheck(cp_offset, checked_up_to); |
| } |
| } |
| } |
| } |
| |
| |
| int TextNode::Length() { |
| TextElement elm = elms_->last(); |
| ASSERT(elm.cp_offset >= 0); |
| if (elm.type == TextElement::ATOM) { |
| return elm.cp_offset + elm.data.u_atom->data().length(); |
| } else { |
| return elm.cp_offset + 1; |
| } |
| } |
| |
| |
| bool TextNode::SkipPass(int int_pass, bool ignore_case) { |
| TextEmitPassType pass = static_cast<TextEmitPassType>(int_pass); |
| if (ignore_case) { |
| return pass == SIMPLE_CHARACTER_MATCH; |
| } else { |
| return pass == NON_LETTER_CHARACTER_MATCH || pass == CASE_CHARACTER_MATCH; |
| } |
| } |
| |
| |
| // This generates the code to match a text node. A text node can contain |
| // straight character sequences (possibly to be matched in a case-independent |
| // way) and character classes. For efficiency we do not do this in a single |
| // pass from left to right. Instead we pass over the text node several times, |
| // emitting code for some character positions every time. See the comment on |
| // TextEmitPass for details. |
| void TextNode::Emit(RegExpCompiler* compiler, Trace* trace) { |
| LimitResult limit_result = LimitVersions(compiler, trace); |
| if (limit_result == DONE) return; |
| ASSERT(limit_result == CONTINUE); |
| |
| if (trace->cp_offset() + Length() > RegExpMacroAssembler::kMaxCPOffset) { |
| compiler->SetRegExpTooBig(); |
| return; |
| } |
| |
| if (compiler->ascii()) { |
| int dummy = 0; |
| TextEmitPass(compiler, NON_ASCII_MATCH, false, trace, false, &dummy); |
| } |
| |
| bool first_elt_done = false; |
| int bound_checked_to = trace->cp_offset() - 1; |
| bound_checked_to += trace->bound_checked_up_to(); |
| |
| // If a character is preloaded into the current character register then |
| // check that now. |
| if (trace->characters_preloaded() == 1) { |
| for (int pass = kFirstRealPass; pass <= kLastPass; pass++) { |
| if (!SkipPass(pass, compiler->ignore_case())) { |
| TextEmitPass(compiler, |
| static_cast<TextEmitPassType>(pass), |
| true, |
| trace, |
| false, |
| &bound_checked_to); |
| } |
| } |
| first_elt_done = true; |
| } |
| |
| for (int pass = kFirstRealPass; pass <= kLastPass; pass++) { |
| if (!SkipPass(pass, compiler->ignore_case())) { |
| TextEmitPass(compiler, |
| static_cast<TextEmitPassType>(pass), |
| false, |
| trace, |
| first_elt_done, |
| &bound_checked_to); |
| } |
| } |
| |
| Trace successor_trace(*trace); |
| successor_trace.set_at_start(false); |
| successor_trace.AdvanceCurrentPositionInTrace(Length(), compiler); |
| RecursionCheck rc(compiler); |
| on_success()->Emit(compiler, &successor_trace); |
| } |
| |
| |
| void Trace::InvalidateCurrentCharacter() { |
| characters_preloaded_ = 0; |
| } |
| |
| |
| void Trace::AdvanceCurrentPositionInTrace(int by, RegExpCompiler* compiler) { |
| 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->ascii()); |
| cp_offset_ += by; |
| if (cp_offset_ > RegExpMacroAssembler::kMaxCPOffset) { |
| compiler->SetRegExpTooBig(); |
| cp_offset_ = 0; |
| } |
| bound_checked_up_to_ = Max(0, bound_checked_up_to_ - by); |
| } |
| |
| |
| void TextNode::MakeCaseIndependent(bool is_ascii) { |
| int element_count = elms_->length(); |
| for (int i = 0; i < element_count; i++) { |
| TextElement elm = elms_->at(i); |
| if (elm.type == TextElement::CHAR_CLASS) { |
| RegExpCharacterClass* cc = elm.data.u_char_class; |
| // None of the standard character classses is different in the case |
| // independent case and it slows us down if we don't know that. |
| if (cc->is_standard()) continue; |
| ZoneList<CharacterRange>* ranges = cc->ranges(); |
| int range_count = ranges->length(); |
| for (int j = 0; j < range_count; j++) { |
| ranges->at(j).AddCaseEquivalents(ranges, is_ascii); |
| } |
| } |
| } |
| } |
| |
| |
| int TextNode::GreedyLoopTextLength() { |
| TextElement elm = elms_->at(elms_->length() - 1); |
| if (elm.type == TextElement::CHAR_CLASS) { |
| return elm.cp_offset + 1; |
| } else { |
| return elm.cp_offset + elm.data.u_atom->data().length(); |
| } |
| } |
| |
| |
| // Finds the fixed match length of a sequence of nodes that goes from |
| // this alternative and back to this choice node. If there are variable |
| // length nodes or other complications in the way then return a sentinel |
| // value indicating that a greedy loop cannot be constructed. |
| int ChoiceNode::GreedyLoopTextLength(GuardedAlternative* alternative) { |
| int length = 0; |
| RegExpNode* node = alternative->node(); |
| // Later we will generate code for all these text nodes using recursion |
| // so we have to limit the max number. |
| int recursion_depth = 0; |
| while (node != this) { |
| if (recursion_depth++ > RegExpCompiler::kMaxRecursion) { |
| return kNodeIsTooComplexForGreedyLoops; |
| } |
| int node_length = node->GreedyLoopTextLength(); |
| if (node_length == kNodeIsTooComplexForGreedyLoops) { |
| return kNodeIsTooComplexForGreedyLoops; |
| } |
| length += node_length; |
| SeqRegExpNode* seq_node = static_cast<SeqRegExpNode*>(node); |
| node = seq_node->on_success(); |
| } |
| return length; |
| } |
| |
| |
| void LoopChoiceNode::AddLoopAlternative(GuardedAlternative alt) { |
| ASSERT_EQ(loop_node_, NULL); |
| AddAlternative(alt); |
| loop_node_ = alt.node(); |
| } |
| |
| |
| void LoopChoiceNode::AddContinueAlternative(GuardedAlternative alt) { |
| ASSERT_EQ(continue_node_, NULL); |
| AddAlternative(alt); |
| continue_node_ = alt.node(); |
| } |
| |
| |
| void LoopChoiceNode::Emit(RegExpCompiler* compiler, Trace* trace) { |
| RegExpMacroAssembler* macro_assembler = compiler->macro_assembler(); |
| if (trace->stop_node() == this) { |
| int text_length = GreedyLoopTextLength(&(alternatives_->at(0))); |
| ASSERT(text_length != kNodeIsTooComplexForGreedyLoops); |
| // Update the counter-based backtracking info on the stack. This is an |
| // optimization for greedy loops (see below). |
| ASSERT(trace->cp_offset() == text_length); |
| macro_assembler->AdvanceCurrentPosition(text_length); |
| macro_assembler->GoTo(trace->loop_label()); |
| return; |
| } |
| ASSERT(trace->stop_node() == NULL); |
| if (!trace->is_trivial()) { |
| trace->Flush(compiler, this); |
| return; |
| } |
| ChoiceNode::Emit(compiler, trace); |
| } |
| |
| |
| int ChoiceNode::CalculatePreloadCharacters(RegExpCompiler* compiler, |
| bool not_at_start) { |
| int preload_characters = EatsAtLeast(4, 0, not_at_start); |
| if (compiler->macro_assembler()->CanReadUnaligned()) { |
| bool ascii = compiler->ascii(); |
| if (ascii) { |
| if (preload_characters > 4) preload_characters = 4; |
| // We can't preload 3 characters because there is no machine instruction |
| // to do that. We can't just load 4 because we could be reading |
| // beyond the end of the string, which could cause a memory fault. |
| if (preload_characters == 3) preload_characters = 2; |
| } else { |
| if (preload_characters > 2) preload_characters = 2; |
| } |
| } else { |
| if (preload_characters > 1) preload_characters = 1; |
| } |
| return preload_characters; |
| } |
| |
| |
| // This class is used when generating the alternatives in a choice node. It |
| // records the way the alternative is being code generated. |
| class AlternativeGeneration: public Malloced { |
| public: |
| AlternativeGeneration() |
| : possible_success(), |
| expects_preload(false), |
| after(), |
| quick_check_details() { } |
| Label possible_success; |
| bool expects_preload; |
| Label after; |
| QuickCheckDetails quick_check_details; |
| }; |
| |
| |
| // Creates a list of AlternativeGenerations. If the list has a reasonable |
| // size then it is on the stack, otherwise the excess is on the heap. |
| class AlternativeGenerationList { |
| public: |
| explicit AlternativeGenerationList(int count) |
| : alt_gens_(count) { |
| for (int i = 0; i < count && i < kAFew; i++) { |
| alt_gens_.Add(a_few_alt_gens_ + i); |
| } |
| for (int i = kAFew; i < count; i++) { |
| alt_gens_.Add(new AlternativeGeneration()); |
| } |
| } |
| ~AlternativeGenerationList() { |
| for (int i = kAFew; i < alt_gens_.length(); i++) { |
| delete alt_gens_[i]; |
| alt_gens_[i] = NULL; |
| } |
| } |
| |
| AlternativeGeneration* at(int i) { |
| return alt_gens_[i]; |
| } |
| private: |
| static const int kAFew = 10; |
| ZoneList<AlternativeGeneration*> alt_gens_; |
| AlternativeGeneration a_few_alt_gens_[kAFew]; |
| }; |
| |
| |
| /* Code generation for choice nodes. |
| * |
| * We generate quick checks that do a mask and compare to eliminate a |
| * choice. If the quick check succeeds then it jumps to the continuation to |
| * do slow checks and check subsequent nodes. If it fails (the common case) |
| * it falls through to the next choice. |
| * |
| * Here is the desired flow graph. Nodes directly below each other imply |
| * fallthrough. Alternatives 1 and 2 have quick checks. Alternative |
| * 3 doesn't have a quick check so we have to call the slow check. |
| * Nodes are marked Qn for quick checks and Sn for slow checks. The entire |
| * regexp continuation is generated directly after the Sn node, up to the |
| * next GoTo if we decide to reuse some already generated code. Some |
| * nodes expect preload_characters to be preloaded into the current |
| * character register. R nodes do this preloading. Vertices are marked |
| * F for failures and S for success (possible success in the case of quick |
| * nodes). L, V, < and > are used as arrow heads. |
| * |
| * ----------> R |
| * | |
| * V |
| * Q1 -----> S1 |
| * | S / |
| * F| / |
| * | F/ |
| * | / |
| * | R |
| * | / |
| * V L |
| * Q2 -----> S2 |
| * | S / |
| * F| / |
| * | F/ |
| * | / |
| * | R |
| * | / |
| * V L |
| * S3 |
| * | |
| * F| |
| * | |
| * R |
| * | |
| * backtrack V |
| * <----------Q4 |
| * \ F | |
| * \ |S |
| * \ F V |
| * \-----S4 |
| * |
| * For greedy loops we reverse our expectation and expect to match rather |
| * than fail. Therefore we want the loop code to look like this (U is the |
| * unwind code that steps back in the greedy loop). The following alternatives |
| * look the same as above. |
| * _____ |
| * / \ |
| * V | |
| * ----------> S1 | |
| * /| | |
| * / |S | |
| * F/ \_____/ |
| * / |
| * |<----------- |
| * | \ |
| * V \ |
| * Q2 ---> S2 \ |
| * | S / | |
| * F| / | |
| * | F/ | |
| * | / | |
| * | R | |
| * | / | |
| * F VL | |
| * <------U | |
| * back |S | |
| * \______________/ |
| */ |
| |
| |
| void ChoiceNode::Emit(RegExpCompiler* compiler, Trace* trace) { |
| RegExpMacroAssembler* macro_assembler = compiler->macro_assembler(); |
| int choice_count = alternatives_->length(); |
| #ifdef DEBUG |
| for (int i = 0; i < choice_count - 1; i++) { |
| GuardedAlternative alternative = alternatives_->at(i); |
| ZoneList<Guard*>* guards = alternative.guards(); |
| int guard_count = (guards == NULL) ? 0 : guards->length(); |
| for (int j = 0; j < guard_count; j++) { |
| ASSERT(!trace->mentions_reg(guards->at(j)->reg())); |
| } |
| } |
| #endif |
| |
| LimitResult limit_result = LimitVersions(compiler, trace); |
| if (limit_result == DONE) return; |
| ASSERT(limit_result == CONTINUE); |
| |
| int new_flush_budget = trace->flush_budget() / choice_count; |
| if (trace->flush_budget() == 0 && trace->actions() != NULL) { |
| trace->Flush(compiler, this); |
| return; |
| } |
| |
| RecursionCheck rc(compiler); |
| |
| Trace* current_trace = trace; |
| |
| int text_length = GreedyLoopTextLength(&(alternatives_->at(0))); |
| bool greedy_loop = false; |
| Label greedy_loop_label; |
| Trace counter_backtrack_trace; |
| counter_backtrack_trace.set_backtrack(&greedy_loop_label); |
| if (not_at_start()) counter_backtrack_trace.set_at_start(false); |
| |
| if (choice_count > 1 && text_length != kNodeIsTooComplexForGreedyLoops) { |
| // Here we have special handling for greedy loops containing only text nodes |
| // and other simple nodes. These are handled by pushing the current |
| // position on the stack and then incrementing the current position each |
| // time around the switch. On backtrack we decrement the current position |
| // and check it against the pushed value. This avoids pushing backtrack |
| // information for each iteration of the loop, which could take up a lot of |
| // space. |
| greedy_loop = true; |
| ASSERT(trace->stop_node() == NULL); |
| macro_assembler->PushCurrentPosition(); |
| current_trace = &counter_backtrack_trace; |
| Label greedy_match_failed; |
| Trace greedy_match_trace; |
| if (not_at_start()) greedy_match_trace.set_at_start(false); |
| greedy_match_trace.set_backtrack(&greedy_match_failed); |
| Label loop_label; |
| macro_assembler->Bind(&loop_label); |
| greedy_match_trace.set_stop_node(this); |
| greedy_match_trace.set_loop_label(&loop_label); |
| alternatives_->at(0).node()->Emit(compiler, &greedy_match_trace); |
| macro_assembler->Bind(&greedy_match_failed); |
| } |
| |
| Label second_choice; // For use in greedy matches. |
| macro_assembler->Bind(&second_choice); |
| |
| int first_normal_choice = greedy_loop ? 1 : 0; |
| |
| int preload_characters = |
| CalculatePreloadCharacters(compiler, |
| current_trace->at_start() == Trace::FALSE); |
| bool preload_is_current = |
| (current_trace->characters_preloaded() == preload_characters); |
| bool preload_has_checked_bounds = preload_is_current; |
| |
| AlternativeGenerationList alt_gens(choice_count); |
| |
| // For now we just call all choices one after the other. The idea ultimately |
| // is to use the Dispatch table to try only the relevant ones. |
| for (int i = first_normal_choice; i < choice_count; i++) { |
| GuardedAlternative alternative = alternatives_->at(i); |
| AlternativeGeneration* alt_gen = alt_gens.at(i); |
| alt_gen->quick_check_details.set_characters(preload_characters); |
| ZoneList<Guard*>* guards = alternative.guards(); |
| int guard_count = (guards == NULL) ? 0 : guards->length(); |
| Trace new_trace(*current_trace); |
| new_trace.set_characters_preloaded(preload_is_current ? |
| preload_characters : |
| 0); |
| if (preload_has_checked_bounds) { |
| new_trace.set_bound_checked_up_to(preload_characters); |
| } |
| new_trace.quick_check_performed()->Clear(); |
| if (not_at_start_) new_trace.set_at_start(Trace::FALSE); |
| alt_gen->expects_preload = preload_is_current; |
| bool generate_full_check_inline = false; |
| if (FLAG_regexp_optimization && |
| try_to_emit_quick_check_for_alternative(i) && |
| alternative.node()->EmitQuickCheck(compiler, |
| &new_trace, |
| preload_has_checked_bounds, |
| &alt_gen->possible_success, |
| &alt_gen->quick_check_details, |
| i < choice_count - 1)) { |
| // Quick check was generated for this choice. |
| preload_is_current = true; |
| preload_has_checked_bounds = true; |
| // On the last choice in the ChoiceNode we generated the quick |
| // check to fall through on possible success. So now we need to |
| // generate the full check inline. |
| if (i == choice_count - 1) { |
| macro_assembler->Bind(&alt_gen->possible_success); |
| new_trace.set_quick_check_performed(&alt_gen->quick_check_details); |
| new_trace.set_characters_preloaded(preload_characters); |
| new_trace.set_bound_checked_up_to(preload_characters); |
| generate_full_check_inline = true; |
| } |
| } else if (alt_gen->quick_check_details.cannot_match()) { |
| if (i == choice_count - 1 && !greedy_loop) { |
| macro_assembler->GoTo(trace->backtrack()); |
| } |
| continue; |
| } else { |
| // No quick check was generated. Put the full code here. |
| // If this is not the first choice then there could be slow checks from |
| // previous cases that go here when they fail. There's no reason to |
| // insist that they preload characters since the slow check we are about |
| // to generate probably can't use it. |
| if (i != first_normal_choice) { |
| alt_gen->expects_preload = false; |
| new_trace.InvalidateCurrentCharacter(); |
| } |
| if (i < choice_count - 1) { |
| new_trace.set_backtrack(&alt_gen->after); |
| } |
| generate_full_check_inline = true; |
| } |
| if (generate_full_check_inline) { |
| if (new_trace.actions() != NULL) { |
| new_trace.set_flush_budget(new_flush_budget); |
| } |
| for (int j = 0; j < guard_count; j++) { |
| GenerateGuard(macro_assembler, guards->at(j), &new_trace); |
| } |
| alternative.node()->Emit(compiler, &new_trace); |
| preload_is_current = false; |
| } |
| macro_assembler->Bind(&alt_gen->after); |
| } |
| if (greedy_loop) { |
| macro_assembler->Bind(&greedy_loop_label); |
| // If we have unwound to the bottom then backtrack. |
| macro_assembler->CheckGreedyLoop(trace->backtrack()); |
| // Otherwise try the second priority at an earlier position. |
| macro_assembler->AdvanceCurrentPosition(-text_length); |
| macro_assembler->GoTo(&second_choice); |
| } |
| |
| // At this point we need to generate slow checks for the alternatives where |
| // the quick check was inlined. We can recognize these because the associated |
| // label was bound. |
| for (int i = first_normal_choice; i < choice_count - 1; i++) { |
| AlternativeGeneration* alt_gen = alt_gens.at(i); |
| Trace new_trace(*current_trace); |
| // If there are actions to be flushed we have to limit how many times |
| // they are flushed. Take the budget of the parent trace and distribute |
| // it fairly amongst the children. |
| if (new_trace.actions() != NULL) { |
| new_trace.set_flush_budget(new_flush_budget); |
| } |
| EmitOutOfLineContinuation(compiler, |
| &new_trace, |
| alternatives_->at(i), |
| alt_gen, |
| preload_characters, |
| alt_gens.at(i + 1)->expects_preload); |
| } |
| } |
| |
| |
| void ChoiceNode::EmitOutOfLineContinuation(RegExpCompiler* compiler, |
| Trace* trace, |
| GuardedAlternative alternative, |
| AlternativeGeneration* alt_gen, |
| int preload_characters, |
| bool next_expects_preload) { |
| if (!alt_gen->possible_success.is_linked()) return; |
| |
| RegExpMacroAssembler* macro_assembler = compiler->macro_assembler(); |
| macro_assembler->Bind(&alt_gen->possible_success); |
| Trace out_of_line_trace(*trace); |
| out_of_line_trace.set_characters_preloaded(preload_characters); |
| out_of_line_trace.set_quick_check_performed(&alt_gen->quick_check_details); |
| if (not_at_start_) out_of_line_trace.set_at_start(Trace::FALSE); |
| ZoneList<Guard*>* guards = alternative.guards(); |
| int guard_count = (guards == NULL) ? 0 : guards->length(); |
| if (next_expects_preload) { |
| Label reload_current_char; |
| out_of_line_trace.set_backtrack(&reload_current_char); |
| for (int j = 0; j < guard_count; j++) { |
| GenerateGuard(macro_assembler, guards->at(j), &out_of_line_trace); |
| } |
| alternative.node()->Emit(compiler, &out_of_line_trace); |
| macro_assembler->Bind(&reload_current_char); |
| // Reload the current character, since the next quick check expects that. |
| // We don't need to check bounds here because we only get into this |
| // code through a quick check which already did the checked load. |
| macro_assembler->LoadCurrentCharacter(trace->cp_offset(), |
| NULL, |
| false, |
| preload_characters); |
| macro_assembler->GoTo(&(alt_gen->after)); |
| } else { |
| out_of_line_trace.set_backtrack(&(alt_gen->after)); |
| for (int j = 0; j < guard_count; j++) { |
| GenerateGuard(macro_assembler, guards->at(j), &out_of_line_trace); |
| } |
| alternative.node()->Emit(compiler, &out_of_line_trace); |
| } |
| } |
| |
| |
| void ActionNode::Emit(RegExpCompiler* compiler, Trace* trace) { |
| RegExpMacroAssembler* assembler = compiler->macro_assembler(); |
| LimitResult limit_result = LimitVersions(compiler, trace); |
| if (limit_result == DONE) return; |
| ASSERT(limit_result == CONTINUE); |
| |
| RecursionCheck rc(compiler); |
| |
| switch (type_) { |
| case STORE_POSITION: { |
| Trace::DeferredCapture |
| new_capture(data_.u_position_register.reg, |
| data_.u_position_register.is_capture, |
| trace); |
| Trace new_trace = *trace; |
| new_trace.add_action(&new_capture); |
| on_success()->Emit(compiler, &new_trace); |
| break; |
| } |
| case INCREMENT_REGISTER: { |
| Trace::DeferredIncrementRegister |
| new_increment(data_.u_increment_register.reg); |
| Trace new_trace = *trace; |
| new_trace.add_action(&new_increment); |
| on_success()->Emit(compiler, &new_trace); |
| break; |
| } |
| case SET_REGISTER: { |
| Trace::DeferredSetRegister |
| new_set(data_.u_store_register.reg, data_.u_store_register.value); |
| Trace new_trace = *trace; |
| new_trace.add_action(&new_set); |
| on_success()->Emit(compiler, &new_trace); |
| break; |
| } |
| case CLEAR_CAPTURES: { |
| Trace::DeferredClearCaptures |
| new_capture(Interval(data_.u_clear_captures.range_from, |
| data_.u_clear_captures.range_to)); |
| Trace new_trace = *trace; |
| new_trace.add_action(&new_capture); |
| on_success()->Emit(compiler, &new_trace); |
| break; |
| } |
| case BEGIN_SUBMATCH: |
| if (!trace->is_trivial()) { |
| trace->Flush(compiler, this); |
| } else { |
| assembler->WriteCurrentPositionToRegister( |
| data_.u_submatch.current_position_register, 0); |
| assembler->WriteStackPointerToRegister( |
| data_.u_submatch.stack_pointer_register); |
| on_success()->Emit(compiler, trace); |
| } |
| break; |
| case EMPTY_MATCH_CHECK: { |
| int start_pos_reg = data_.u_empty_match_check.start_register; |
| int stored_pos = 0; |
| int rep_reg = data_.u_empty_match_check.repetition_register; |
| bool has_minimum = (rep_reg != RegExpCompiler::kNoRegister); |
| bool know_dist = trace->GetStoredPosition(start_pos_reg, &stored_pos); |
| if (know_dist && !has_minimum && stored_pos == trace->cp_offset()) { |
| // If we know we haven't advanced and there is no minimum we |
| // can just backtrack immediately. |
| assembler->GoTo(trace->backtrack()); |
| } else if (know_dist && stored_pos < trace->cp_offset()) { |
| // If we know we've advanced we can generate the continuation |
| // immediately. |
| on_success()->Emit(compiler, trace); |
| } else if (!trace->is_trivial()) { |
| trace->Flush(compiler, this); |
| } else { |
| Label skip_empty_check; |
| // If we have a minimum number of repetitions we check the current |
| // number first and skip the empty check if it's not enough. |
| if (has_minimum) { |
| int limit = data_.u_empty_match_check.repetition_limit; |
| assembler->IfRegisterLT(rep_reg, limit, &skip_empty_check); |
| } |
| // If the match is empty we bail out, otherwise we fall through |
| // to the on-success continuation. |
| assembler->IfRegisterEqPos(data_.u_empty_match_check.start_register, |
| trace->backtrack()); |
| assembler->Bind(&skip_empty_check); |
| on_success()->Emit(compiler, trace); |
| } |
| break; |
| } |
| case POSITIVE_SUBMATCH_SUCCESS: { |
| if (!trace->is_trivial()) { |
| trace->Flush(compiler, this); |
| return; |
| } |
| assembler->ReadCurrentPositionFromRegister( |
| data_.u_submatch.current_position_register); |
| assembler->ReadStackPointerFromRegister( |
| data_.u_submatch.stack_pointer_register); |
| int clear_register_count = data_.u_submatch.clear_register_count; |
| if (clear_register_count == 0) { |
| on_success()->Emit(compiler, trace); |
| return; |
| } |
| int clear_registers_from = data_.u_submatch.clear_register_from; |
| Label clear_registers_backtrack; |
| Trace new_trace = *trace; |
| new_trace.set_backtrack(&clear_registers_backtrack); |
| on_success()->Emit(compiler, &new_trace); |
| |
| assembler->Bind(&clear_registers_backtrack); |
| int clear_registers_to = clear_registers_from + clear_register_count - 1; |
| assembler->ClearRegisters(clear_registers_from, clear_registers_to); |
| |
| ASSERT(trace->backtrack() == NULL); |
| assembler->Backtrack(); |
| return; |
| } |
| default: |
| UNREACHABLE(); |
| } |
| } |
| |
| |
| void BackReferenceNode::Emit(RegExpCompiler* compiler, Trace* trace) { |
| RegExpMacroAssembler* assembler = compiler->macro_assembler(); |
| if (!trace->is_trivial()) { |
| trace->Flush(compiler, this); |
| return; |
| } |
| |
| LimitResult limit_result = LimitVersions(compiler, trace); |
| if (limit_result == DONE) return; |
| ASSERT(limit_result == CONTINUE); |
| |
| RecursionCheck rc(compiler); |
| |
| ASSERT_EQ(start_reg_ + 1, end_reg_); |
| if (compiler->ignore_case()) { |
| assembler->CheckNotBackReferenceIgnoreCase(start_reg_, |
| trace->backtrack()); |
| } else { |
| assembler->CheckNotBackReference(start_reg_, trace->backtrack()); |
| } |
| on_success()->Emit(compiler, trace); |
| } |
| |
| |
| // ------------------------------------------------------------------- |
| // Dot/dotty output |
| |
| |
| #ifdef DEBUG |
| |
| |
| class DotPrinter: public NodeVisitor { |
| public: |
| explicit DotPrinter(bool ignore_case) |
| : ignore_case_(ignore_case), |
| stream_(&alloc_) { } |
| void PrintNode(const char* label, RegExpNode* node); |
| void Visit(RegExpNode* node); |
| void PrintAttributes(RegExpNode* from); |
| StringStream* stream() { return &stream_; } |
| void PrintOnFailure(RegExpNode* from, RegExpNode* to); |
| #define DECLARE_VISIT(Type) \ |
| virtual void Visit##Type(Type##Node* that); |
| FOR_EACH_NODE_TYPE(DECLARE_VISIT) |
| #undef DECLARE_VISIT |
| private: |
| bool ignore_case_; |
| HeapStringAllocator alloc_; |
| StringStream stream_; |
| }; |
| |
| |
| void DotPrinter::PrintNode(const char* label, RegExpNode* node) { |
| stream()->Add("digraph G {\n graph [label=\""); |
| for (int i = 0; label[i]; i++) { |
| switch (label[i]) { |
| case '\\': |
| stream()->Add("\\\\"); |
| break; |
| case '"': |
| stream()->Add("\""); |
| break; |
| default: |
| stream()->Put(label[i]); |
| break; |
| } |
| } |
| stream()->Add("\"];\n"); |
| Visit(node); |
| stream()->Add("}\n"); |
| printf("%s", *(stream()->ToCString())); |
| } |
| |
| |
| void DotPrinter::Visit(RegExpNode* node) { |
| if (node->info()->visited) return; |
| node->info()->visited = true; |
| node->Accept(this); |
| } |
| |
| |
| void DotPrinter::PrintOnFailure(RegExpNode* from, RegExpNode* on_failure) { |
| stream()->Add(" n%p -> n%p [style=dotted];\n", from, on_failure); |
| Visit(on_failure); |
| } |
| |
| |
| class TableEntryBodyPrinter { |
| public: |
| TableEntryBodyPrinter(StringStream* stream, ChoiceNode* choice) |
| : stream_(stream), choice_(choice) { } |
| void Call(uc16 from, DispatchTable::Entry entry) { |
| OutSet* out_set = entry.out_set(); |
| for (unsigned i = 0; i < OutSet::kFirstLimit; i++) { |
| if (out_set->Get(i)) { |
| stream()->Add(" n%p:s%io%i -> n%p;\n", |
| choice(), |
| from, |
| i, |
| choice()->alternatives()->at(i).node()); |
| } |
| } |
| } |
| private: |
| StringStream* stream() { return stream_; } |
| ChoiceNode* choice() { return choice_; } |
| StringStream* stream_; |
| ChoiceNode* choice_; |
| }; |
| |
| |
| class TableEntryHeaderPrinter { |
| public: |
| explicit TableEntryHeaderPrinter(StringStream* stream) |
| : first_(true), stream_(stream) { } |
| void Call(uc16 from, DispatchTable::Entry entry) { |
| if (first_) { |
| first_ = false; |
| } else { |
| stream()->Add("|"); |
| } |
| stream()->Add("{\\%k-\\%k|{", from, entry.to()); |
| OutSet* out_set = entry.out_set(); |
| int priority = 0; |
| for (unsigned i = 0; i < OutSet::kFirstLimit; i++) { |
| if (out_set->Get(i)) { |
| if (priority > 0) stream()->Add("|"); |
| stream()->Add("<s%io%i> %i", from, i, priority); |
| priority++; |
| } |
| } |
| stream()->Add("}}"); |
| } |
| private: |
| bool first_; |
| StringStream* stream() { return stream_; } |
| StringStream* stream_; |
| }; |
| |
| |
| class AttributePrinter { |
| public: |
| explicit AttributePrinter(DotPrinter* out) |
| : out_(out), first_(true) { } |
| void PrintSeparator() { |
| if (first_) { |
| first_ = false; |
| } else { |
| out_->stream()->Add("|"); |
| } |
| } |
| void PrintBit(const char* name, bool value) { |
| if (!value) return; |
| PrintSeparator(); |
| out_->stream()->Add("{%s}", name); |
| } |
| void PrintPositive(const char* name, int value) { |
| if (value < 0) return; |
| PrintSeparator(); |
| out_->stream()->Add("{%s|%x}", name, value); |
| } |
| private: |
| DotPrinter* out_; |
| bool first_; |
| }; |
| |
| |
| void DotPrinter::PrintAttributes(RegExpNode* that) { |
| stream()->Add(" a%p [shape=Mrecord, color=grey, fontcolor=grey, " |
| "margin=0.1, fontsize=10, label=\"{", |
| that); |
| AttributePrinter printer(this); |
| NodeInfo* info = that->info(); |
| printer.PrintBit("NI", info->follows_newline_interest); |
| printer.PrintBit("WI", info->follows_word_interest); |
| printer.PrintBit("SI", info->follows_start_interest); |
| Label* label = that->label(); |
| if (label->is_bound()) |
| printer.PrintPositive("@", label->pos()); |
| stream()->Add("}\"];\n"); |
| stream()->Add(" a%p -> n%p [style=dashed, color=grey, " |
| "arrowhead=none];\n", that, that); |
| } |
| |
| |
| static const bool kPrintDispatchTable = false; |
| void DotPrinter::VisitChoice(ChoiceNode* that) { |
| if (kPrintDispatchTable) { |
| stream()->Add(" n%p [shape=Mrecord, label=\"", that); |
| TableEntryHeaderPrinter header_printer(stream()); |
| that->GetTable(ignore_case_)->ForEach(&header_printer); |
| stream()->Add("\"]\n", that); |
| PrintAttributes(that); |
| TableEntryBodyPrinter body_printer(stream(), that); |
| that->GetTable(ignore_case_)->ForEach(&body_printer); |
| } else { |
| stream()->Add(" n%p [shape=Mrecord, label=\"?\"];\n", that); |
| for (int i = 0; i < that->alternatives()->length(); i++) { |
| GuardedAlternative alt = that->alternatives()->at(i); |
| stream()->Add(" n%p -> n%p;\n", that, alt.node()); |
| } |
| } |
| for (int i = 0; i < that->alternatives()->length(); i++) { |
| GuardedAlternative alt = that->alternatives()->at(i); |
| alt.node()->Accept(this); |
| } |
| } |
| |
| |
| void DotPrinter::VisitText(TextNode* that) { |
| stream()->Add(" n%p [label=\"", that); |
| for (int i = 0; i < that->elements()->length(); i++) { |
| if (i > 0) stream()->Add(" "); |
| TextElement elm = that->elements()->at(i); |
| switch (elm.type) { |
| case TextElement::ATOM: { |
| stream()->Add("'%w'", elm.data.u_atom->data()); |
| break; |
| } |
| case TextElement::CHAR_CLASS: { |
| RegExpCharacterClass* node = elm.data.u_char_class; |
| stream()->Add("["); |
| if (node->is_negated()) |
| stream()->Add("^"); |
| for (int j = 0; j < node->ranges()->length(); j++) { |
| CharacterRange range = node->ranges()->at(j); |
| stream()->Add("%k-%k", range.from(), range.to()); |
| } |
| stream()->Add("]"); |
| break; |
| } |
| default: |
| UNREACHABLE(); |
| } |
| } |
| stream()->Add("\", shape=box, peripheries=2];\n"); |
| PrintAttributes(that); |
| stream()->Add(" n%p -> n%p;\n", that, that->on_success()); |
| Visit(that->on_success()); |
| } |
| |
| |
| void DotPrinter::VisitBackReference(BackReferenceNode* that) { |
| stream()->Add(" n%p [label=\"$%i..$%i\", shape=doubleoctagon];\n", |
| that, |
| that->start_register(), |
| that->end_register()); |
| PrintAttributes(that); |
| stream()->Add(" n%p -> n%p;\n", that, that->on_success()); |
| Visit(that->on_success()); |
| } |
| |
| |
| void DotPrinter::VisitEnd(EndNode* that) { |
| stream()->Add(" n%p [style=bold, shape=point];\n", that); |
| PrintAttributes(that); |
| } |
| |
| |
| void DotPrinter::VisitAssertion(AssertionNode* that) { |
| stream()->Add(" n%p [", that); |
| switch (that->type()) { |
| case AssertionNode::AT_END: |
| stream()->Add("label=\"$\", shape=septagon"); |
| break; |
| case AssertionNode::AT_START: |
| stream()->Add("label=\"^\", shape=septagon"); |
| break; |
| case AssertionNode::AT_BOUNDARY: |
| stream()->Add("label=\"\\b\", shape=septagon"); |
| break; |
| case AssertionNode::AT_NON_BOUNDARY: |
| stream()->Add("label=\"\\B\", shape=septagon"); |
| break; |
| case AssertionNode::AFTER_NEWLINE: |
| stream()->Add("label=\"(?<=\\n)\", shape=septagon"); |
| break; |
| case AssertionNode::AFTER_WORD_CHARACTER: |
| stream()->Add("label=\"(?<=\\w)\", shape=septagon"); |
| break; |
| case AssertionNode::AFTER_NONWORD_CHARACTER: |
| stream()->Add("label=\"(?<=\\W)\", shape=septagon"); |
| break; |
| } |
| stream()->Add("];\n"); |
| PrintAttributes(that); |
| RegExpNode* successor = that->on_success(); |
| stream()->Add(" n%p -> n%p;\n", that, successor); |
| Visit(successor); |
| } |
| |
| |
| void DotPrinter::VisitAction(ActionNode* that) { |
| stream()->Add(" n%p [", that); |
| switch (that->type_) { |
| case ActionNode::SET_REGISTER: |
| stream()->Add("label=\"$%i:=%i\", shape=octagon", |
| that->data_.u_store_register.reg, |
| that->data_.u_store_register.value); |
| break; |
| case ActionNode::INCREMENT_REGISTER: |
| stream()->Add("label=\"$%i++\", shape=octagon", |
| that->data_.u_increment_register.reg); |
| break; |
| case ActionNode::STORE_POSITION: |
| stream()->Add("label=\"$%i:=$pos\", shape=octagon", |
| that->data_.u_position_register.reg); |
| break; |
| case ActionNode::BEGIN_SUBMATCH: |
| stream()->Add("label=\"$%i:=$pos,begin\", shape=septagon", |
| that->data_.u_submatch.current_position_register); |
| break; |
| case ActionNode::POSITIVE_SUBMATCH_SUCCESS: |
| stream()->Add("label=\"escape\", shape=septagon"); |
| break; |
| case ActionNode::EMPTY_MATCH_CHECK: |
| stream()->Add("label=\"$%i=$pos?,$%i<%i?\", shape=septagon", |
| that->data_.u_empty_match_check.start_register, |
| that->data_.u_empty_match_check.repetition_register, |
| that->data_.u_empty_match_check.repetition_limit); |
| break; |
| case ActionNode::CLEAR_CAPTURES: { |
| stream()->Add("label=\"clear $%i to $%i\", shape=septagon", |
| that->data_.u_clear_captures.range_from, |
| that->data_.u_clear_captures.range_to); |
| break; |
| } |
| } |
| stream()->Add("];\n"); |
| PrintAttributes(that); |
| RegExpNode* successor = that->on_success(); |
| stream()->Add(" n%p -> n%p;\n", that, successor); |
| Visit(successor); |
| } |
| |
| |
| class DispatchTableDumper { |
| public: |
| explicit DispatchTableDumper(StringStream* stream) : stream_(stream) { } |
| void Call(uc16 key, DispatchTable::Entry entry); |
| StringStream* stream() { return stream_; } |
| private: |
| StringStream* stream_; |
| }; |
| |
| |
| void DispatchTableDumper::Call(uc16 key, DispatchTable::Entry entry) { |
| stream()->Add("[%k-%k]: {", key, entry.to()); |
| OutSet* set = entry.out_set(); |
| bool first = true; |
| for (unsigned i = 0; i < OutSet::kFirstLimit; i++) { |
| if (set->Get(i)) { |
| if (first) { |
| first = false; |
| } else { |
| stream()->Add(", "); |
| } |
| stream()->Add("%i", i); |
| } |
| } |
| stream()->Add("}\n"); |
| } |
| |
| |
| void DispatchTable::Dump() { |
| HeapStringAllocator alloc; |
| StringStream stream(&alloc); |
| DispatchTableDumper dumper(&stream); |
| tree()->ForEach(&dumper); |
| OS::PrintError("%s", *stream.ToCString()); |
| } |
| |
| |
| void RegExpEngine::DotPrint(const char* label, |
| RegExpNode* node, |
| bool ignore_case) { |
| DotPrinter printer(ignore_case); |
| printer.PrintNode(label, node); |
| } |
| |
| |
| #endif // DEBUG |
| |
| |
| // ------------------------------------------------------------------- |
| // Tree to graph conversion |
| |
| static const int kSpaceRangeCount = 20; |
| static const int kSpaceRangeAsciiCount = 4; |
| static const uc16 kSpaceRanges[kSpaceRangeCount] = { 0x0009, 0x000D, 0x0020, |
| 0x0020, 0x00A0, 0x00A0, 0x1680, 0x1680, 0x180E, 0x180E, 0x2000, 0x200A, |
| 0x2028, 0x2029, 0x202F, 0x202F, 0x205F, 0x205F, 0x3000, 0x3000 }; |
| |
| static const int kWordRangeCount = 8; |
| static const uc16 kWordRanges[kWordRangeCount] = { '0', '9', 'A', 'Z', '_', |
| '_', 'a', 'z' }; |
| |
| static const int kDigitRangeCount = 2; |
| static const uc16 kDigitRanges[kDigitRangeCount] = { '0', '9' }; |
| |
| static const int kLineTerminatorRangeCount = 6; |
| static const uc16 kLineTerminatorRanges[kLineTerminatorRangeCount] = { 0x000A, |
| 0x000A, 0x000D, 0x000D, 0x2028, 0x2029 }; |
| |
| RegExpNode* RegExpAtom::ToNode(RegExpCompiler* compiler, |
| RegExpNode* on_success) { |
| ZoneList<TextElement>* elms = new ZoneList<TextElement>(1); |
| elms->Add(TextElement::Atom(this)); |
| return new TextNode(elms, on_success); |
| } |
| |
| |
| RegExpNode* RegExpText::ToNode(RegExpCompiler* compiler, |
| RegExpNode* on_success) { |
| return new TextNode(elements(), on_success); |
| } |
| |
| static bool CompareInverseRanges(ZoneList<CharacterRange>* ranges, |
| const uc16* special_class, |
| int length) { |
| ASSERT(ranges->length() != 0); |
| ASSERT(length != 0); |
| ASSERT(special_class[0] != 0); |
| if (ranges->length() != (length >> 1) + 1) { |
| return false; |
| } |
| CharacterRange range = ranges->at(0); |
| if (range.from() != 0) { |
| return false; |
| } |
| for (int i = 0; i < length; i += 2) { |
| if (special_class[i] != (range.to() + 1)) { |
| return false; |
| } |
| range = ranges->at((i >> 1) + 1); |
| if (special_class[i+1] != range.from() - 1) { |
| return false; |
| } |
| } |
| if (range.to() != 0xffff) { |
| return false; |
| } |
| return true; |
| } |
| |
| |
| static bool CompareRanges(ZoneList<CharacterRange>* ranges, |
| const uc16* special_class, |
| int length) { |
| if (ranges->length() * 2 != length) { |
| return false; |
| } |
| for (int i = 0; i < length; i += 2) { |
| CharacterRange range = ranges->at(i >> 1); |
| if (range.from() != special_class[i] || range.to() != special_class[i+1]) { |
| return false; |
| } |
| } |
| return true; |
| } |
| |
| |
| bool RegExpCharacterClass::is_standard() { |
| // TODO(lrn): Remove need for this function, by not throwing away information |
| // along the way. |
| if (is_negated_) { |
| return false; |
| } |
| if (set_.is_standard()) { |
| return true; |
| } |
| if (CompareRanges(set_.ranges(), kSpaceRanges, kSpaceRangeCount)) { |
| set_.set_standard_set_type('s'); |
| return true; |
| } |
| if (CompareInverseRanges(set_.ranges(), kSpaceRanges, kSpaceRangeCount)) { |
| set_.set_standard_set_type('S'); |
| return true; |
| } |
| if (CompareInverseRanges(set_.ranges(), |
| kLineTerminatorRanges, |
| kLineTerminatorRangeCount)) { |
| set_.set_standard_set_type('.'); |
| return true; |
| } |
| if (CompareRanges(set_.ranges(), |
| kLineTerminatorRanges, |
| kLineTerminatorRangeCount)) { |
| set_.set_standard_set_type('n'); |
| return true; |
| } |
| if (CompareRanges(set_.ranges(), kWordRanges, kWordRangeCount)) { |
| set_.set_standard_set_type('w'); |
| return true; |
| } |
| if (CompareInverseRanges(set_.ranges(), kWordRanges, kWordRangeCount)) { |
| set_.set_standard_set_type('W'); |
| return true; |
| } |
| return false; |
| } |
| |
| |
| RegExpNode* RegExpCharacterClass::ToNode(RegExpCompiler* compiler, |
| RegExpNode* on_success) { |
| return new TextNode(this, on_success); |
| } |
| |
| |
| RegExpNode* RegExpDisjunction::ToNode(RegExpCompiler* compiler, |
| RegExpNode* on_success) { |
| ZoneList<RegExpTree*>* alternatives = this->alternatives(); |
| int length = alternatives->length(); |
| ChoiceNode* result = new ChoiceNode(length); |
| for (int i = 0; i < length; i++) { |
| GuardedAlternative alternative(alternatives->at(i)->ToNode(compiler, |
| on_success)); |
| result->AddAlternative(alternative); |
| } |
| return result; |
| } |
| |
| |
| RegExpNode* RegExpQuantifier::ToNode(RegExpCompiler* compiler, |
| RegExpNode* on_success) { |
| return ToNode(min(), |
| max(), |
| is_greedy(), |
| body(), |
| compiler, |
| on_success); |
| } |
| |
| |
| RegExpNode* RegExpQuantifier::ToNode(int min, |
| int max, |
| bool is_greedy, |
| RegExpTree* body, |
| RegExpCompiler* compiler, |
| RegExpNode* on_success, |
| bool not_at_start) { |
| // x{f, t} becomes this: |
| // |
| // (r++)<-. |
| // | ` |
| // | (x) |
| // v ^ |
| // (r=0)-->(?)---/ [if r < t] |
| // | |
| // [if r >= f] \----> ... |
| // |
| |
| // 15.10.2.5 RepeatMatcher algorithm. |
| // The parser has already eliminated the case where max is 0. In the case |
| // where max_match is zero the parser has removed the quantifier if min was |
| // > 0 and removed the atom if min was 0. See AddQuantifierToAtom. |
| |
| // If we know that we cannot match zero length then things are a little |
| // simpler since we don't need to make the special zero length match check |
| // from step 2.1. If the min and max are small we can unroll a little in |
| // this case. |
| static const int kMaxUnrolledMinMatches = 3; // Unroll (foo)+ and (foo){3,} |
| static const int kMaxUnrolledMaxMatches = 3; // Unroll (foo)? and (foo){x,3} |
| if (max == 0) return on_success; // This can happen due to recursion. |
| bool body_can_be_empty = (body->min_match() == 0); |
| int body_start_reg = RegExpCompiler::kNoRegister; |
| Interval capture_registers = body->CaptureRegisters(); |
| bool needs_capture_clearing = !capture_registers.is_empty(); |
| if (body_can_be_empty) { |
| body_start_reg = compiler->AllocateRegister(); |
| } else if (FLAG_regexp_optimization && !needs_capture_clearing) { |
| // Only unroll if there are no captures and the body can't be |
| // empty. |
| if (min > 0 && min <= kMaxUnrolledMinMatches) { |
| int new_max = (max == kInfinity) ? max : max - min; |
| // Recurse once to get the loop or optional matches after the fixed ones. |
| RegExpNode* answer = ToNode( |
| 0, new_max, is_greedy, body, compiler, on_success, true); |
| // Unroll the forced matches from 0 to min. This can cause chains of |
| // TextNodes (which the parser does not generate). These should be |
| // combined if it turns out they hinder good code generation. |
| for (int i = 0; i < min; i++) { |
| answer = body->ToNode(compiler, answer); |
| } |
| return answer; |
| } |
| if (max <= kMaxUnrolledMaxMatches) { |
| ASSERT(min == 0); |
| // Unroll the optional matches up to max. |
| RegExpNode* answer = on_success; |
| for (int i = 0; i < max; i++) { |
| ChoiceNode* alternation = new ChoiceNode(2); |
| if (is_greedy) { |
| alternation->AddAlternative(GuardedAlternative(body->ToNode(compiler, |
| answer))); |
| alternation->AddAlternative(GuardedAlternative(on_success)); |
| } else { |
| alternation->AddAlternative(GuardedAlternative(on_success)); |
| alternation->AddAlternative(GuardedAlternative(body->ToNode(compiler, |
| answer))); |
| } |
| answer = alternation; |
| if (not_at_start) alternation->set_not_at_start(); |
| } |
| return answer; |
| } |
| } |
| bool has_min = min > 0; |
| bool has_max = max < RegExpTree::kInfinity; |
| bool needs_counter = has_min || has_max; |
| int reg_ctr = needs_counter |
| ? compiler->AllocateRegister() |
| : RegExpCompiler::kNoRegister; |
| LoopChoiceNode* center = new LoopChoiceNode(body->min_match() == 0); |
| if (not_at_start) center->set_not_at_start(); |
| RegExpNode* loop_return = needs_counter |
| ? static_cast<RegExpNode*>(ActionNode::IncrementRegister(reg_ctr, center)) |
| : static_cast<RegExpNode*>(center); |
| if (body_can_be_empty) { |
| // If the body can be empty we need to check if it was and then |
| // backtrack. |
| loop_return = ActionNode::EmptyMatchCheck(body_start_reg, |
| reg_ctr, |
| min, |
| loop_return); |
| } |
| RegExpNode* body_node = body->ToNode(compiler, loop_return); |
| if (body_can_be_empty) { |
| // If the body can be empty we need to store the start position |
| // so we can bail out if it was empty. |
| body_node = ActionNode::StorePosition(body_start_reg, false, body_node); |
| } |
| if (needs_capture_clearing) { |
| // Before entering the body of this loop we need to clear captures. |
| body_node = ActionNode::ClearCaptures(capture_registers, body_node); |
| } |
| GuardedAlternative body_alt(body_node); |
| if (has_max) { |
| Guard* body_guard = new Guard(reg_ctr, Guard::LT, max); |
| body_alt.AddGuard(body_guard); |
| } |
| GuardedAlternative rest_alt(on_success); |
| if (has_min) { |
| Guard* rest_guard = new Guard(reg_ctr, Guard::GEQ, min); |
| rest_alt.AddGuard(rest_guard); |
| } |
| if (is_greedy) { |
| center->AddLoopAlternative(body_alt); |
| center->AddContinueAlternative(rest_alt); |
| } else { |
| center->AddContinueAlternative(rest_alt); |
| center->AddLoopAlternative(body_alt); |
| } |
| if (needs_counter) { |
| return ActionNode::SetRegister(reg_ctr, 0, center); |
| } else { |
| return center; |
| } |
| } |
| |
| |
| RegExpNode* RegExpAssertion::ToNode(RegExpCompiler* compiler, |
| RegExpNode* on_success) { |
| NodeInfo info; |
| switch (type()) { |
| case START_OF_LINE: |
| return AssertionNode::AfterNewline(on_success); |
| case START_OF_INPUT: |
| return AssertionNode::AtStart(on_success); |
| case BOUNDARY: |
| return AssertionNode::AtBoundary(on_success); |
| case NON_BOUNDARY: |
| return AssertionNode::AtNonBoundary(on_success); |
| case END_OF_INPUT: |
| return AssertionNode::AtEnd(on_success); |
| case END_OF_LINE: { |
| // Compile $ in multiline regexps as an alternation with a positive |
| // lookahead in one side and an end-of-input on the other side. |
| // We need two registers for the lookahead. |
| int stack_pointer_register = compiler->AllocateRegister(); |
| int position_register = compiler->AllocateRegister(); |
| // The ChoiceNode to distinguish between a newline and end-of-input. |
| ChoiceNode* result = new ChoiceNode(2); |
| // Create a newline atom. |
| ZoneList<CharacterRange>* newline_ranges = |
| new ZoneList<CharacterRange>(3); |
| CharacterRange::AddClassEscape('n', newline_ranges); |
| RegExpCharacterClass* newline_atom = new RegExpCharacterClass('n'); |
| TextNode* newline_matcher = new TextNode( |
| newline_atom, |
| ActionNode::PositiveSubmatchSuccess(stack_pointer_register, |
| position_register, |
| 0, // No captures inside. |
| -1, // Ignored if no captures. |
| on_success)); |
| // Create an end-of-input matcher. |
| RegExpNode* end_of_line = ActionNode::BeginSubmatch( |
| stack_pointer_register, |
| position_register, |
| newline_matcher); |
| // Add the two alternatives to the ChoiceNode. |
| GuardedAlternative eol_alternative(end_of_line); |
| result->AddAlternative(eol_alternative); |
| GuardedAlternative end_alternative(AssertionNode::AtEnd(on_success)); |
| result->AddAlternative(end_alternative); |
| return result; |
| } |
| default: |
| UNREACHABLE(); |
| } |
| return on_success; |
| } |
| |
| |
| RegExpNode* RegExpBackReference::ToNode(RegExpCompiler* compiler, |
| RegExpNode* on_success) { |
| return new BackReferenceNode(RegExpCapture::StartRegister(index()), |
| RegExpCapture::EndRegister(index()), |
| on_success); |
| } |
| |
| |
| RegExpNode* RegExpEmpty::ToNode(RegExpCompiler* compiler, |
| RegExpNode* on_success) { |
| return on_success; |
| } |
| |
| |
| RegExpNode* RegExpLookahead::ToNode(RegExpCompiler* compiler, |
| RegExpNode* on_success) { |
| int stack_pointer_register = compiler->AllocateRegister(); |
| int position_register = compiler->AllocateRegister(); |
| |
| const int registers_per_capture = 2; |
| const int register_of_first_capture = 2; |
| int register_count = capture_count_ * registers_per_capture; |
| int register_start = |
| register_of_first_capture + capture_from_ * registers_per_capture; |
| |
| RegExpNode* success; |
| if (is_positive()) { |
| RegExpNode* node = ActionNode::BeginSubmatch( |
| stack_pointer_register, |
| position_register, |
| body()->ToNode( |
| compiler, |
| ActionNode::PositiveSubmatchSuccess(stack_pointer_register, |
| position_register, |
| register_count, |
| register_start, |
| on_success))); |
| return node; |
| } else { |
| // We use a ChoiceNode for a negative lookahead because it has most of |
| // the characteristics we need. It has the body of the lookahead as its |
| // first alternative and the expression after the lookahead of the second |
| // alternative. If the first alternative succeeds then the |
| // NegativeSubmatchSuccess will unwind the stack including everything the |
| // choice node set up and backtrack. If the first alternative fails then |
| // the second alternative is tried, which is exactly the desired result |
| // for a negative lookahead. The NegativeLookaheadChoiceNode is a special |
| // ChoiceNode that knows to ignore the first exit when calculating quick |
| // checks. |
| GuardedAlternative body_alt( |
| body()->ToNode( |
| compiler, |
| success = new NegativeSubmatchSuccess(stack_pointer_register, |
| position_register, |
| register_count, |
| register_start))); |
| ChoiceNode* choice_node = |
| new NegativeLookaheadChoiceNode(body_alt, |
| GuardedAlternative(on_success)); |
| return ActionNode::BeginSubmatch(stack_pointer_register, |
| position_register, |
| choice_node); |
| } |
| } |
| |
| |
| RegExpNode* RegExpCapture::ToNode(RegExpCompiler* compiler, |
| RegExpNode* on_success) { |
| return ToNode(body(), index(), compiler, on_success); |
| } |
| |
| |
| RegExpNode* RegExpCapture::ToNode(RegExpTree* body, |
| int index, |
| RegExpCompiler* compiler, |
| RegExpNode* on_success) { |
| int start_reg = RegExpCapture::StartRegister(index); |
| int end_reg = RegExpCapture::EndRegister(index); |
| RegExpNode* store_end = ActionNode::StorePosition(end_reg, true, on_success); |
| RegExpNode* body_node = body->ToNode(compiler, store_end); |
| return ActionNode::StorePosition(start_reg, true, body_node); |
| } |
| |
| |
| RegExpNode* RegExpAlternative::ToNode(RegExpCompiler* compiler, |
| RegExpNode* on_success) { |
| ZoneList<RegExpTree*>* children = nodes(); |
| RegExpNode* current = on_success; |
| for (int i = children->length() - 1; i >= 0; i--) { |
| current = children->at(i)->ToNode(compiler, current); |
| } |
| return current; |
| } |
| |
| |
| static void AddClass(const uc16* elmv, |
| int elmc, |
| ZoneList<CharacterRange>* ranges) { |
| for (int i = 0; i < elmc; i += 2) { |
| ASSERT(elmv[i] <= elmv[i + 1]); |
| ranges->Add(CharacterRange(elmv[i], elmv[i + 1])); |
| } |
| } |
| |
| |
| static void AddClassNegated(const uc16 *elmv, |
| int elmc, |
| ZoneList<CharacterRange>* ranges) { |
| ASSERT(elmv[0] != 0x0000); |
| ASSERT(elmv[elmc-1] != String::kMaxUC16CharCode); |
| uc16 last = 0x0000; |
| for (int i = 0; i < elmc; i += 2) { |
| ASSERT(last <= elmv[i] - 1); |
| ASSERT(elmv[i] <= elmv[i + 1]); |
| ranges->Add(CharacterRange(last, elmv[i] - 1)); |
| last = elmv[i + 1] + 1; |
| } |
| ranges->Add(CharacterRange(last, String::kMaxUC16CharCode)); |
| } |
| |
| |
| void CharacterRange::AddClassEscape(uc16 type, |
| ZoneList<CharacterRange>* ranges) { |
| switch (type) { |
| case 's': |
| AddClass(kSpaceRanges, kSpaceRangeCount, ranges); |
| break; |
| case 'S': |
| AddClassNegated(kSpaceRanges, kSpaceRangeCount, ranges); |
| break; |
| case 'w': |
| AddClass(kWordRanges, kWordRangeCount, ranges); |
| break; |
| case 'W': |
| AddClassNegated(kWordRanges, kWordRangeCount, ranges); |
| break; |
| case 'd': |
| AddClass(kDigitRanges, kDigitRangeCount, ranges); |
| break; |
| case 'D': |
| AddClassNegated(kDigitRanges, kDigitRangeCount, ranges); |
| break; |
| case '.': |
| AddClassNegated(kLineTerminatorRanges, |
| kLineTerminatorRangeCount, |
| ranges); |
| break; |
| // This is not a character range as defined by the spec but a |
| // convenient shorthand for a character class that matches any |
| // character. |
| case '*': |
| ranges->Add(CharacterRange::Everything()); |
| break; |
| // This is the set of characters matched by the $ and ^ symbols |
| // in multiline mode. |
| case 'n': |
| AddClass(kLineTerminatorRanges, |
| kLineTerminatorRangeCount, |
| ranges); |
| break; |
| default: |
| UNREACHABLE(); |
| } |
| } |
| |
| |
| Vector<const uc16> CharacterRange::GetWordBounds() { |
| return Vector<const uc16>(kWordRanges, kWordRangeCount); |
| } |
| |
| |
| class CharacterRangeSplitter { |
| public: |
| CharacterRangeSplitter(ZoneList<CharacterRange>** included, |
| ZoneList<CharacterRange>** excluded) |
| : included_(included), |
| excluded_(excluded) { } |
| void Call(uc16 from, DispatchTable::Entry entry); |
| |
| static const int kInBase = 0; |
| static const int kInOverlay = 1; |
| |
| private: |
| ZoneList<CharacterRange>** included_; |
| ZoneList<CharacterRange>** excluded_; |
| }; |
| |
| |
| void CharacterRangeSplitter::Call(uc16 from, DispatchTable::Entry entry) { |
| if (!entry.out_set()->Get(kInBase)) return; |
| ZoneList<CharacterRange>** target = entry.out_set()->Get(kInOverlay) |
| ? included_ |
| : excluded_; |
| if (*target == NULL) *target = new ZoneList<CharacterRange>(2); |
| (*target)->Add(CharacterRange(entry.from(), entry.to())); |
| } |
| |
| |
| void CharacterRange::Split(ZoneList<CharacterRange>* base, |
| Vector<const uc16> overlay, |
| ZoneList<CharacterRange>** included, |
| ZoneList<CharacterRange>** excluded) { |
| ASSERT_EQ(NULL, *included); |
| ASSERT_EQ(NULL, *excluded); |
| DispatchTable table; |
| for (int i = 0; i < base->length(); i++) |
| table.AddRange(base->at(i), CharacterRangeSplitter::kInBase); |
| for (int i = 0; i < overlay.length(); i += 2) { |
| table.AddRange(CharacterRange(overlay[i], overlay[i+1]), |
| CharacterRangeSplitter::kInOverlay); |
| } |
| CharacterRangeSplitter callback(included, excluded); |
| table.ForEach(&callback); |
| } |
| |
| |
| static void AddUncanonicals(ZoneList<CharacterRange>* ranges, |
| int bottom, |
| int top); |
| |
| |
| void CharacterRange::AddCaseEquivalents(ZoneList<CharacterRange>* ranges, |
| bool is_ascii) { |
| uc16 bottom = from(); |
| uc16 top = to(); |
| if (is_ascii) { |
| if (bottom > String::kMaxAsciiCharCode) return; |
| if (top > String::kMaxAsciiCharCode) top = String::kMaxAsciiCharCode; |
| } |
| unibrow::uchar chars[unibrow::Ecma262UnCanonicalize::kMaxWidth]; |
| if (top == bottom) { |
| // If this is a singleton we just expand the one character. |
| int length = uncanonicalize.get(bottom, '\0', chars); |
| for (int i = 0; i < length; i++) { |
| uc32 chr = chars[i]; |
| if (chr != bottom) { |
| ranges->Add(CharacterRange::Singleton(chars[i])); |
| } |
| } |
| } else { |
| // If this is a range we expand the characters block by block, |
| // expanding contiguous subranges (blocks) one at a time. |
| // The approach is as follows. For a given start character we |
| // look up the remainder of the block that contains it (represented |
| // by the end point), for instance we find 'z' if the character |
| // is 'c'. A block is characterized by the property |
| // that all characters uncanonicalize in the same way, except that |
| // each entry in the result is incremented by the distance from the first |
| // element. So a-z is a block because 'a' uncanonicalizes to ['a', 'A'] and |
| // the k'th letter uncanonicalizes to ['a' + k, 'A' + k]. |
| // Once we've found the end point we look up its uncanonicalization |
| // and produce a range for each element. For instance for [c-f] |
| // we look up ['z', 'Z'] and produce [c-f] and [C-F]. We then only |
| // add a range if it is not already contained in the input, so [c-f] |
| // will be skipped but [C-F] will be added. If this range is not |
| // completely contained in a block we do this for all the blocks |
| // covered by the range (handling characters that is not in a block |
| // as a "singleton block"). |
| unibrow::uchar range[unibrow::Ecma262UnCanonicalize::kMaxWidth]; |
| int pos = bottom; |
| while (pos < top) { |
| int length = canonrange.get(pos, '\0', range); |
| uc16 block_end; |
| if (length == 0) { |
| block_end = pos; |
| } else { |
| ASSERT_EQ(1, length); |
| block_end = range[0]; |
| } |
| int end = (block_end > top) ? top : block_end; |
| length = uncanonicalize.get(block_end, '\0', range); |
| for (int i = 0; i < length; i++) { |
| uc32 c = range[i]; |
| uc16 range_from = c - (block_end - pos); |
| uc16 range_to = c - (block_end - end); |
| if (!(bottom <= range_from && range_to <= top)) { |
| ranges->Add(CharacterRange(range_from, range_to)); |
| } |
| } |
| pos = end + 1; |
| } |
| } |
| } |
| |
| |
| bool CharacterRange::IsCanonical(ZoneList<CharacterRange>* ranges) { |
| ASSERT_NOT_NULL(ranges); |
| int n = ranges->length(); |
| if (n <= 1) return true; |
| int max = ranges->at(0).to(); |
| for (int i = 1; i < n; i++) { |
| CharacterRange next_range = ranges->at(i); |
| if (next_range.from() <= max + 1) return false; |
| max = next_range.to(); |
| } |
| return true; |
| } |
| |
| SetRelation CharacterRange::WordCharacterRelation( |
| ZoneList<CharacterRange>* range) { |
| ASSERT(IsCanonical(range)); |
| int i = 0; // Word character range index. |
| int j = 0; // Argument range index. |
| ASSERT_NE(0, kWordRangeCount); |
| SetRelation result; |
| if (range->length() == 0) { |
| result.SetElementsInSecondSet(); |
| return result; |
| } |
| CharacterRange argument_range = range->at(0); |
| CharacterRange word_range = CharacterRange(kWordRanges[0], kWordRanges[1]); |
| while (i < kWordRangeCount && j < range->length()) { |
| // Check the two ranges for the five cases: |
| // - no overlap. |
| // - partial overlap (there are elements in both ranges that isn't |
| // in the other, and there are also elements that are in both). |
| // - argument range entirely inside word range. |
| // - word range entirely inside argument range. |
| // - ranges are completely equal. |
| |
| // First check for no overlap. The earlier range is not in the other set. |
| if (argument_range.from() > word_range.to()) { |
| // Ranges are disjoint. The earlier word range contains elements that |
| // cannot be in the argument set. |
| result.SetElementsInSecondSet(); |
| } else if (word_range.from() > argument_range.to()) { |
| // Ranges are disjoint. The earlier argument range contains elements that |
| // cannot be in the word set. |
| result.SetElementsInFirstSet(); |
| } else if (word_range.from() <= argument_range.from() && |
| word_range.to() >= argument_range.from()) { |
| result.SetElementsInBothSets(); |
| // argument range completely inside word range. |
| if (word_range.from() < argument_range.from() || |
| word_range.to() > argument_range.from()) { |
| result.SetElementsInSecondSet(); |
| } |
| } else if (word_range.from() >= argument_range.from() && |
| word_range.to() <= argument_range.from()) { |
| result.SetElementsInBothSets(); |
| result.SetElementsInFirstSet(); |
| } else { |
| // There is overlap, and neither is a subrange of the other |
| result.SetElementsInFirstSet(); |
| result.SetElementsInSecondSet(); |
| result.SetElementsInBothSets(); |
| } |
| if (result.NonTrivialIntersection()) { |
| // The result is as (im)precise as we can possibly make it. |
| return result; |
| } |
| // Progress the range(s) with minimal to-character. |
| uc16 word_to = word_range.to(); |
| uc16 argument_to = argument_range.to(); |
| if (argument_to <= word_to) { |
| j++; |
| if (j < range->length()) { |
| argument_range = range->at(j); |
| } |
| } |
| if (word_to <= argument_to) { |
| i += 2; |
| if (i < kWordRangeCount) { |
| word_range = CharacterRange(kWordRanges[i], kWordRanges[i + 1]); |
| } |
| } |
| } |
| // Check if anything wasn't compared in the loop. |
| if (i < kWordRangeCount) { |
| // word range contains something not in argument range. |
| result.SetElementsInSecondSet(); |
| } else if (j < range->length()) { |
| // Argument range contains something not in word range. |
| result.SetElementsInFirstSet(); |
| } |
| |
| return result; |
| } |
| |
| |
| static void AddUncanonicals(ZoneList<CharacterRange>* ranges, |
| int bottom, |
| int top) { |
| unibrow::uchar chars[unibrow::Ecma262UnCanonicalize::kMaxWidth]; |
| // Zones with no case mappings. There is a DEBUG-mode loop to assert that |
| // this table is correct. |
| // 0x0600 - 0x0fff |
| // 0x1100 - 0x1cff |
| // 0x2000 - 0x20ff |
| // 0x2200 - 0x23ff |
| // 0x2500 - 0x2bff |
| // 0x2e00 - 0xa5ff |
| // 0xa800 - 0xfaff |
| // 0xfc00 - 0xfeff |
| const int boundary_count = 18; |
| int boundaries[] = { |
| 0x600, 0x1000, 0x1100, 0x1d00, 0x2000, 0x2100, 0x2200, 0x2400, 0x2500, |
| 0x2c00, 0x2e00, 0xa600, 0xa800, 0xfb00, 0xfc00, 0xff00}; |
| |
| // Special ASCII rule from spec can save us some work here. |
| if (bottom == 0x80 && top == 0xffff) return; |
| |
| if (top <= boundaries[0]) { |
| CharacterRange range(bottom, top); |
| range.AddCaseEquivalents(ranges, false); |
| return; |
| } |
| |
| // Split up very large ranges. This helps remove ranges where there are no |
| // case mappings. |
| for (int i = 0; i < boundary_count; i++) { |
| if (bottom < boundaries[i] && top >= boundaries[i]) { |
| AddUncanonicals(ranges, bottom, boundaries[i] - 1); |
| AddUncanonicals(ranges, boundaries[i], top); |
| return; |
| } |
| } |
| |
| // If we are completely in a zone with no case mappings then we are done. |
| for (int i = 0; i < boundary_count; i += 2) { |
| if (bottom >= boundaries[i] && top < boundaries[i + 1]) { |
| #ifdef DEBUG |
| for (int j = bottom; j <= top; j++) { |
| unsigned current_char = j; |
| int length = uncanonicalize.get(current_char, '\0', chars); |
| for (int k = 0; k < length; k++) { |
| ASSERT(chars[k] == current_char); |
| } |
| } |
| #endif |
| return; |
| } |
| } |
| |
| // Step through the range finding equivalent characters. |
| ZoneList<unibrow::uchar> *characters = new ZoneList<unibrow::uchar>(100); |
| for (int i = bottom; i <= top; i++) { |
| int length = uncanonicalize.get(i, '\0', chars); |
| for (int j = 0; j < length; j++) { |
| uc32 chr = chars[j]; |
| if (chr != i && (chr < bottom || chr > top)) { |
| characters->Add(chr); |
| } |
| } |
| } |
| |
| // Step through the equivalent characters finding simple ranges and |
| // adding ranges to the character class. |
| if (characters->length() > 0) { |
| int new_from = characters->at(0); |
| int new_to = new_from; |
| for (int i = 1; i < characters->length(); i++) { |
| int chr = characters->at(i); |
| if (chr == new_to + 1) { |
| new_to++; |
| } else { |
| if (new_to == new_from) { |
| ranges->Add(CharacterRange::Singleton(new_from)); |
| } else { |
| ranges->Add(CharacterRange(new_from, new_to)); |
| } |
| new_from = new_to = chr; |
| } |
| } |
| if (new_to == new_from) { |
| ranges->Add(CharacterRange::Singleton(new_from)); |
| } else { |
| ranges->Add(CharacterRange(new_from, new_to)); |
| } |
| } |
| } |
| |
| |
| ZoneList<CharacterRange>* CharacterSet::ranges() { |
| if (ranges_ == NULL) { |
| ranges_ = new ZoneList<CharacterRange>(2); |
| CharacterRange::AddClassEscape(standard_set_type_, ranges_); |
| } |
| return ranges_; |
| } |
| |
| |
| // Move a number of elements in a zonelist to another position |
| // in the same list. Handles overlapping source and target areas. |
| static void MoveRanges(ZoneList<CharacterRange>* list, |
| int from, |
| int to, |
| int count) { |
| // Ranges are potentially overlapping. |
| if (from < to) { |
| for (int i = count - 1; i >= 0; i--) { |
| list->at(to + i) = list->at(from + i); |
| } |
| } else { |
| for (int i = 0; i < count; i++) { |
| list->at(to + i) = list->at(from + i); |
| } |
| } |
| } |
| |
| |
| static int InsertRangeInCanonicalList(ZoneList<CharacterRange>* list, |
| int count, |
| CharacterRange insert) { |
| // Inserts a range into list[0..count[, which must be sorted |
| // by from value and non-overlapping and non-adjacent, using at most |
| // list[0..count] for the result. Returns the number of resulting |
| // canonicalized ranges. Inserting a range may collapse existing ranges into |
| // fewer ranges, so the return value can be anything in the range 1..count+1. |
| uc16 from = insert.from(); |
| uc16 to = insert.to(); |
| int start_pos = 0; |
| int end_pos = count; |
| for (int i = count - 1; i >= 0; i--) { |
| CharacterRange current = list->at(i); |
| if (current.from() > to + 1) { |
| end_pos = i; |
| } else if (current.to() + 1 < from) { |
| start_pos = i + 1; |
| break; |
| } |
| } |
| |
| // Inserted range overlaps, or is adjacent to, ranges at positions |
| // [start_pos..end_pos[. Ranges before start_pos or at or after end_pos are |
| // not affected by the insertion. |
| // If start_pos == end_pos, the range must be inserted before start_pos. |
| // if start_pos < end_pos, the entire range from start_pos to end_pos |
| // must be merged with the insert range. |
| |
| if (start_pos == end_pos) { |
| // Insert between existing ranges at position start_pos. |
| if (start_pos < count) { |
| MoveRanges(list, start_pos, start_pos + 1, count - start_pos); |
| } |
| list->at(start_pos) = insert; |
| return count + 1; |
| } |
| if (start_pos + 1 == end_pos) { |
| // Replace single existing range at position start_pos. |
| CharacterRange to_replace = list->at(start_pos); |
| int new_from = Min(to_replace.from(), from); |
| int new_to = Max(to_replace.to(), to); |
| list->at(start_pos) = CharacterRange(new_from, new_to); |
| return count; |
| } |
| // Replace a number of existing ranges from start_pos to end_pos - 1. |
| // Move the remaining ranges down. |
| |
| int new_from = Min(list->at(start_pos).from(), from); |
| int new_to = Max(list->at(end_pos - 1).to(), to); |
| if (end_pos < count) { |
| MoveRanges(list, end_pos, start_pos + 1, count - end_pos); |
| } |
| list->at(start_pos) = CharacterRange(new_from, new_to); |
| return count - (end_pos - start_pos) + 1; |
| } |
| |
| |
| void CharacterSet::Canonicalize() { |
| // Special/default classes are always considered canonical. The result |
| // of calling ranges() will be sorted. |
| if (ranges_ == NULL) return; |
| CharacterRange::Canonicalize(ranges_); |
| } |
| |
| |
| void CharacterRange::Canonicalize(ZoneList<CharacterRange>* character_ranges) { |
| if (character_ranges->length() <= 1) return; |
| // Check whether ranges are already canonical (increasing, non-overlapping, |
| // non-adjacent). |
| int n = character_ranges->length(); |
| int max = character_ranges->at(0).to(); |
| int i = 1; |
| while (i < n) { |
| CharacterRange current = character_ranges->at(i); |
| if (current.from() <= max + 1) { |
| break; |
| } |
| max = current.to(); |
| i++; |
| } |
| // Canonical until the i'th range. If that's all of them, we are done. |
| if (i == n) return; |
| |
| // The ranges at index i and forward are not canonicalized. Make them so by |
| // doing the equivalent of insertion sort (inserting each into the previous |
| // list, in order). |
| // Notice that inserting a range can reduce the number of ranges in the |
| // result due to combining of adjacent and overlapping ranges. |
| int read = i; // Range to insert. |
| int num_canonical = i; // Length of canonicalized part of list. |
| do { |
| num_canonical = InsertRangeInCanonicalList(character_ranges, |
| num_canonical, |
| character_ranges->at(read)); |
| read++; |
| } while (read < n); |
| character_ranges->Rewind(num_canonical); |
| |
| ASSERT(CharacterRange::IsCanonical(character_ranges)); |
| } |
| |
| |
| // Utility function for CharacterRange::Merge. Adds a range at the end of |
| // a canonicalized range list, if necessary merging the range with the last |
| // range of the list. |
| static void AddRangeToSet(ZoneList<CharacterRange>* set, CharacterRange range) { |
| if (set == NULL) return; |
| ASSERT(set->length() == 0 || set->at(set->length() - 1).to() < range.from()); |
| int n = set->length(); |
| if (n > 0) { |
| CharacterRange lastRange = set->at(n - 1); |
| if (lastRange.to() == range.from() - 1) { |
| set->at(n - 1) = CharacterRange(lastRange.from(), range.to()); |
| return; |
| } |
| } |
| set->Add(range); |
| } |
| |
| |
| static void AddRangeToSelectedSet(int selector, |
| ZoneList<CharacterRange>* first_set, |
| ZoneList<CharacterRange>* second_set, |
| ZoneList<CharacterRange>* intersection_set, |
| CharacterRange range) { |
| switch (selector) { |
| case kInsideFirst: |
| AddRangeToSet(first_set, range); |
| break; |
| case kInsideSecond: |
| AddRangeToSet(second_set, range); |
| break; |
| case kInsideBoth: |
| AddRangeToSet(intersection_set, range); |
| break; |
| } |
| } |
| |
| |
| |
| void CharacterRange::Merge(ZoneList<CharacterRange>* first_set, |
| ZoneList<CharacterRange>* second_set, |
| ZoneList<CharacterRange>* first_set_only_out, |
| ZoneList<CharacterRange>* second_set_only_out, |
| ZoneList<CharacterRange>* both_sets_out) { |
| // Inputs are canonicalized. |
| ASSERT(CharacterRange::IsCanonical(first_set)); |
| ASSERT(CharacterRange::IsCanonical(second_set)); |
| // Outputs are empty, if applicable. |
| ASSERT(first_set_only_out == NULL || first_set_only_out->length() == 0); |
| ASSERT(second_set_only_out == NULL || second_set_only_out->length() == 0); |
| ASSERT(both_sets_out == NULL || both_sets_out->length() == 0); |
| |
| // Merge sets by iterating through the lists in order of lowest "from" value, |
| // and putting intervals into one of three sets. |
| |
| if (first_set->length() == 0) { |
| second_set_only_out->AddAll(*second_set); |
| return; |
| } |
| if (second_set->length() == 0) { |
| first_set_only_out->AddAll(*first_set); |
| return; |
| } |
| // Indices into input lists. |
| int i1 = 0; |
| int i2 = 0; |
| // Cache length of input lists. |
| int n1 = first_set->length(); |
| int n2 = second_set->length(); |
| // Current range. May be invalid if state is kInsideNone. |
| int from = 0; |
| int to = -1; |
| // Where current range comes from. |
| int state = kInsideNone; |
| |
| while (i1 < n1 || i2 < n2) { |
| CharacterRange next_range; |
| int range_source; |
| if (i2 == n2 || |
| (i1 < n1 && first_set->at(i1).from() < second_set->at(i2).from())) { |
| // Next smallest element is in first set. |
| next_range = first_set->at(i1++); |
| range_source = kInsideFirst; |
| } else { |
| // Next smallest element is in second set. |
| next_range = second_set->at(i2++); |
| range_source = kInsideSecond; |
| } |
| if (to < next_range.from()) { |
| // Ranges disjoint: |current| |next| |
| AddRangeToSelectedSet(state, |
| first_set_only_out, |
| second_set_only_out, |
| both_sets_out, |
| CharacterRange(from, to)); |
| from = next_range.from(); |
| to = next_range.to(); |
| state = range_source; |
| } else { |
| if (from < next_range.from()) { |
| AddRangeToSelectedSet(state, |
| first_set_only_out, |
| second_set_only_out, |
| both_sets_out, |
| CharacterRange(from, next_range.from()-1)); |
| } |
| if (to < next_range.to()) { |
| // Ranges overlap: |current| |
| // |next| |
| AddRangeToSelectedSet(state | range_source, |
| first_set_only_out, |
| second_set_only_out, |
| both_sets_out, |
| CharacterRange(next_range.from(), to)); |
| from = to + 1; |
| to = next_range.to(); |
| state = range_source; |
| } else { |
| // Range included: |current| , possibly ending at same character. |
| // |next| |
| AddRangeToSelectedSet( |
| state | range_source, |
| first_set_only_out, |
| second_set_only_out, |
| both_sets_out, |
| CharacterRange(next_range.from(), next_range.to())); |
| from = next_range.to() + 1; |
| // If ranges end at same character, both ranges are consumed completely. |
| if (next_range.to() == to) state = kInsideNone; |
| } |
| } |
| } |
| AddRangeToSelectedSet(state, |
| first_set_only_out, |
| second_set_only_out, |
| both_sets_out, |
| CharacterRange(from, to)); |
| } |
| |
| |
| void CharacterRange::Negate(ZoneList<CharacterRange>* ranges, |
| ZoneList<CharacterRange>* negated_ranges) { |
| ASSERT(CharacterRange::IsCanonical(ranges)); |
| ASSERT_EQ(0, negated_ranges->length()); |
| int range_count = ranges->length(); |
| uc16 from = 0; |
| int i = 0; |
| if (range_count > 0 && ranges->at(0).from() == 0) { |
| from = ranges->at(0).to(); |
| i = 1; |
| } |
| while (i < range_count) { |
| CharacterRange range = ranges->at(i); |
| negated_ranges->Add(CharacterRange(from + 1, range.from() - 1)); |
| from = range.to(); |
| i++; |
| } |
| if (from < String::kMaxUC16CharCode) { |
| negated_ranges->Add(CharacterRange(from + 1, String::kMaxUC16CharCode)); |
| } |
| } |
| |
| |
| |
| // ------------------------------------------------------------------- |
| // Interest propagation |
| |
| |
| RegExpNode* RegExpNode::TryGetSibling(NodeInfo* info) { |
| for (int i = 0; i < siblings_.length(); i++) { |
| RegExpNode* sibling = siblings_.Get(i); |
| if (sibling->info()->Matches(info)) |
| return sibling; |
| } |
| return NULL; |
| } |
| |
| |
| RegExpNode* RegExpNode::EnsureSibling(NodeInfo* info, bool* cloned) { |
| ASSERT_EQ(false, *cloned); |
| siblings_.Ensure(this); |
| RegExpNode* result = TryGetSibling(info); |
| if (result != NULL) return result; |
| result = this->Clone(); |
| NodeInfo* new_info = result->info(); |
| new_info->ResetCompilationState(); |
| new_info->AddFromPreceding(info); |
| AddSibling(result); |
| *cloned = true; |
| return result; |
| } |
| |
| |
| template <class C> |
| static RegExpNode* PropagateToEndpoint(C* node, NodeInfo* info) { |
| NodeInfo full_info(*node->info()); |
| full_info.AddFromPreceding(info); |
| bool cloned = false; |
| return RegExpNode::EnsureSibling(node, &full_info, &cloned); |
| } |
| |
| |
| // ------------------------------------------------------------------- |
| // Splay tree |
| |
| |
| OutSet* OutSet::Extend(unsigned value) { |
| if (Get(value)) |
| return this; |
| if (successors() != NULL) { |
| for (int i = 0; i < successors()->length(); i++) { |
| OutSet* successor = successors()->at(i); |
| if (successor->Get(value)) |
| return successor; |
| } |
| } else { |
| successors_ = new ZoneList<OutSet*>(2); |
| } |
| OutSet* result = new OutSet(first_, remaining_); |
| result->Set(value); |
| successors()->Add(result); |
| return result; |
| } |
| |
| |
| void OutSet::Set(unsigned value) { |
| if (value < kFirstLimit) { |
| first_ |= (1 << value); |
| } else { |
| if (remaining_ == NULL) |
| remaining_ = new ZoneList<unsigned>(1); |
| if (remaining_->is_empty() || !remaining_->Contains(value)) |
| remaining_->Add(value); |
| } |
| } |
| |
| |
| bool OutSet::Get(unsigned value) { |
| if (value < kFirstLimit) { |
| return (first_ & (1 << value)) != 0; |
| } else if (remaining_ == NULL) { |
| return false; |
| } else { |
| return remaining_->Contains(value); |
| } |
| } |
| |
| |
| const uc16 DispatchTable::Config::kNoKey = unibrow::Utf8::kBadChar; |
| const DispatchTable::Entry DispatchTable::Config::kNoValue; |
| |
| |
| void DispatchTable::AddRange(CharacterRange full_range, int value) { |
| CharacterRange current = full_range; |
| if (tree()->is_empty()) { |
| // If this is the first range we just insert into the table. |
| ZoneSplayTree<Config>::Locator loc; |
| ASSERT_RESULT(tree()->Insert(current.from(), &loc)); |
| loc.set_value(Entry(current.from(), current.to(), empty()->Extend(value))); |
| return; |
| } |
| // First see if there is a range to the left of this one that |
| // overlaps. |
| ZoneSplayTree<Config>::Locator loc; |
| if (tree()->FindGreatestLessThan(current.from(), &loc)) { |
| Entry* entry = &loc.value(); |
| // If we've found a range that overlaps with this one, and it |
| // starts strictly to the left of this one, we have to fix it |
| // because the following code only handles ranges that start on |
| // or after the start point of the range we're adding. |
| if (entry->from() < current.from() && entry->to() >= current.from()) { |
| // Snap the overlapping range in half around the start point of |
| // the range we're adding. |
| CharacterRange left(entry->from(), current.from() - 1); |
| CharacterRange right(current.from(), entry->to()); |
| // The left part of the overlapping range doesn't overlap. |
| // Truncate the whole entry to be just the left part. |
| entry->set_to(left.to()); |
| // The right part is the one that overlaps. We add this part |
| // to the map and let the next step deal with merging it with |
| // the range we're adding. |
| ZoneSplayTree<Config>::Locator loc; |
| ASSERT_RESULT(tree()->Insert(right.from(), &loc)); |
| loc.set_value(Entry(right.from(), |
| right.to(), |
| entry->out_set())); |
| } |
| } |
| while (current.is_valid()) { |
| if (tree()->FindLeastGreaterThan(current.from(), &loc) && |
| (loc.value().from() <= current.to()) && |
| (loc.value().to() >= current.from())) { |
| Entry* entry = &loc.value(); |
| // We have overlap. If there is space between the start point of |
| // the range we're adding and where the overlapping range starts |
| // then we have to add a range covering just that space. |
| if (current.from() < entry->from()) { |
| ZoneSplayTree<Config>::Locator ins; |
| ASSERT_RESULT(tree()->Insert(current.from(), &ins)); |
| ins.set_value(Entry(current.from(), |
| entry->from() - 1, |
| empty()->Extend(value))); |
| current.set_from(entry->from()); |
| } |
| ASSERT_EQ(current.from(), entry->from()); |
| // If the overlapping range extends beyond the one we want to add |
| // we have to snap the right part off and add it separately. |
| if (entry->to() > current.to()) { |
| ZoneSplayTree<Config>::Locator ins; |
| ASSERT_RESULT(tree()->Insert(current.to() + 1, &ins)); |
| ins.set_value(Entry(current.to() + 1, |
| entry->to(), |
| entry->out_set())); |
| entry->set_to(current.to()); |
| } |
| ASSERT(entry->to() <= current.to()); |
| // The overlapping range is now completely contained by the range |
| // we're adding so we can just update it and move the start point |
| // of the range we're adding just past it. |
| entry->AddValue(value); |
| // Bail out if the last interval ended at 0xFFFF since otherwise |
| // adding 1 will wrap around to 0. |
| if (entry->to() == String::kMaxUC16CharCode) |
| break; |
| ASSERT(entry->to() + 1 > current.from()); |
| current.set_from(entry->to() + 1); |
| } else { |
| // There is no overlap so we can just add the range |
| ZoneSplayTree<Config>::Locator ins; |
| ASSERT_RESULT(tree()->Insert(current.from(), &ins)); |
| ins.set_value(Entry(current.from(), |
| current.to(), |
| empty()->Extend(value))); |
| break; |
| } |
| } |
| } |
| |
| |
| OutSet* DispatchTable::Get(uc16 value) { |
| ZoneSplayTree<Config>::Locator loc; |
| if (!tree()->FindGreatestLessThan(value, &loc)) |
| return empty(); |
| Entry* entry = &loc.value(); |
| if (value <= entry->to()) |
| return entry->out_set(); |
| else |
| return empty(); |
| } |
| |
| |
| // ------------------------------------------------------------------- |
| // Analysis |
| |
| |
| void Analysis::EnsureAnalyzed(RegExpNode* that) { |
| StackLimitCheck check; |
| if (check.HasOverflowed()) { |
| fail("Stack overflow"); |
| return; |
| } |
| if (that->info()->been_analyzed || that->info()->being_analyzed) |
| return; |
| that->info()->being_analyzed = true; |
| that->Accept(this); |
| that->info()->being_analyzed = false; |
| that->info()->been_analyzed = true; |
| } |
| |
| |
| void Analysis::VisitEnd(EndNode* that) { |
| // nothing to do |
| } |
| |
| |
| void TextNode::CalculateOffsets() { |
| int element_count = elements()->length(); |
| // Set up the offsets of the elements relative to the start. This is a fixed |
| // quantity since a TextNode can only contain fixed-width things. |
| int cp_offset = 0; |
| for (int i = 0; i < element_count; i++) { |
| TextElement& elm = elements()->at(i); |
| elm.cp_offset = cp_offset; |
| if (elm.type == TextElement::ATOM) { |
| cp_offset += elm.data.u_atom->data().length(); |
| } else { |
| cp_offset++; |
| Vector<const uc16> quarks = elm.data.u_atom->data(); |
| } |
| } |
| } |
| |
| |
| void Analysis::VisitText(TextNode* that) { |
| if (ignore_case_) { |
| that->MakeCaseIndependent(is_ascii_); |
| } |
| EnsureAnalyzed(that->on_success()); |
| if (!has_failed()) { |
| that->CalculateOffsets(); |
| } |
| } |
| |
| |
| void Analysis::VisitAction(ActionNode* that) { |
| RegExpNode* target = that->on_success(); |
| EnsureAnalyzed(target); |
| if (!has_failed()) { |
| // If the next node is interested in what it follows then this node |
| // has to be interested too so it can pass the information on. |
| that->info()->AddFromFollowing(target->info()); |
| } |
| } |
| |
| |
| void Analysis::VisitChoice(ChoiceNode* that) { |
| NodeInfo* info = that->info(); |
| for (int i = 0; i < that->alternatives()->length(); i++) { |
| RegExpNode* node = that->alternatives()->at(i).node(); |
| EnsureAnalyzed(node); |
| if (has_failed()) return; |
| // Anything the following nodes need to know has to be known by |
| // this node also, so it can pass it on. |
| info->AddFromFollowing(node->info()); |
| } |
| } |
| |
| |
| void Analysis::VisitLoopChoice(LoopChoiceNode* that) { |
| NodeInfo* info = that->info(); |
| for (int i = 0; i < that->alternatives()->length(); i++) { |
| RegExpNode* node = that->alternatives()->at(i).node(); |
| if (node != that->loop_node()) { |
| EnsureAnalyzed(node); |
| if (has_failed()) return; |
| info->AddFromFollowing(node->info()); |
| } |
| } |
| // Check the loop last since it may need the value of this node |
| // to get a correct result. |
| EnsureAnalyzed(that->loop_node()); |
| if (!has_failed()) { |
| info->AddFromFollowing(that->loop_node()->info()); |
| } |
| } |
| |
| |
| void Analysis::VisitBackReference(BackReferenceNode* that) { |
| EnsureAnalyzed(that->on_success()); |
| } |
| |
| |
| void Analysis::VisitAssertion(AssertionNode* that) { |
| EnsureAnalyzed(that->on_success()); |
| AssertionNode::AssertionNodeType type = that->type(); |
| if (type == AssertionNode::AT_BOUNDARY || |
| type == AssertionNode::AT_NON_BOUNDARY) { |
| // Check if the following character is known to be a word character |
| // or known to not be a word character. |
| ZoneList<CharacterRange>* following_chars = that->FirstCharacterSet(); |
| |
| CharacterRange::Canonicalize(following_chars); |
| |
| SetRelation word_relation = |
| CharacterRange::WordCharacterRelation(following_chars); |
| if (word_relation.Disjoint()) { |
| // Includes the case where following_chars is empty (e.g., end-of-input). |
| // Following character is definitely *not* a word character. |
| type = (type == AssertionNode::AT_BOUNDARY) ? |
| AssertionNode::AFTER_WORD_CHARACTER : |
| AssertionNode::AFTER_NONWORD_CHARACTER; |
| that->set_type(type); |
| } else if (word_relation.ContainedIn()) { |
| // Following character is definitely a word character. |
| type = (type == AssertionNode::AT_BOUNDARY) ? |
| AssertionNode::AFTER_NONWORD_CHARACTER : |
| AssertionNode::AFTER_WORD_CHARACTER; |
| that->set_type(type); |
| } |
| } |
| } |
| |
| |
| ZoneList<CharacterRange>* RegExpNode::FirstCharacterSet() { |
| if (first_character_set_ == NULL) { |
| if (ComputeFirstCharacterSet(kFirstCharBudget) < 0) { |
| // If we can't find an exact solution within the budget, we |
| // set the value to the set of every character, i.e., all characters |
| // are possible. |
| ZoneList<CharacterRange>* all_set = new ZoneList<CharacterRange>(1); |
| all_set->Add(CharacterRange::Everything()); |
| first_character_set_ = all_set; |
| } |
| } |
| return first_character_set_; |
| } |
| |
| |
| int RegExpNode::ComputeFirstCharacterSet(int budget) { |
| // Default behavior is to not be able to determine the first character. |
| return kComputeFirstCharacterSetFail; |
| } |
| |
| |
| int LoopChoiceNode::ComputeFirstCharacterSet(int budget) { |
| budget--; |
| if (budget >= 0) { |
| // Find loop min-iteration. It's the value of the guarded choice node |
| // with a GEQ guard, if any. |
| int min_repetition = 0; |
| |
| for (int i = 0; i <= 1; i++) { |
| GuardedAlternative alternative = alternatives()->at(i); |
| ZoneList<Guard*>* guards = alternative.guards(); |
| if (guards != NULL && guards->length() > 0) { |
| Guard* guard = guards->at(0); |
| if (guard->op() == Guard::GEQ) { |
| min_repetition = guard->value(); |
| break; |
| } |
| } |
| } |
| |
| budget = loop_node()->ComputeFirstCharacterSet(budget); |
| if (budget >= 0) { |
| ZoneList<CharacterRange>* character_set = |
| loop_node()->first_character_set(); |
| if (body_can_be_zero_length() || min_repetition == 0) { |
| budget = continue_node()->ComputeFirstCharacterSet(budget); |
| if (budget < 0) return budget; |
| ZoneList<CharacterRange>* body_set = |
| continue_node()->first_character_set(); |
| ZoneList<CharacterRange>* union_set = |
| new ZoneList<CharacterRange>(Max(character_set->length(), |
| body_set->length())); |
| CharacterRange::Merge(character_set, |
| body_set, |
| union_set, |
| union_set, |
| union_set); |
| character_set = union_set; |
| } |
| set_first_character_set(character_set); |
| } |
| } |
| return budget; |
| } |
| |
| |
| int NegativeLookaheadChoiceNode::ComputeFirstCharacterSet(int budget) { |
| budget--; |
| if (budget >= 0) { |
| GuardedAlternative successor = this->alternatives()->at(1); |
| RegExpNode* successor_node = successor.node(); |
| budget = successor_node->ComputeFirstCharacterSet(budget); |
| if (budget >= 0) { |
| set_first_character_set(successor_node->first_character_set()); |
| } |
| } |
| return budget; |
| } |
| |
| |
| // The first character set of an EndNode is unknowable. Just use the |
| // default implementation that fails and returns all characters as possible. |
| |
| |
| int AssertionNode::ComputeFirstCharacterSet(int budget) { |
| budget -= 1; |
| if (budget >= 0) { |
| switch (type_) { |
| case AT_END: { |
| set_first_character_set(new ZoneList<CharacterRange>(0)); |
| break; |
| } |
| case AT_START: |
| case AT_BOUNDARY: |
| case AT_NON_BOUNDARY: |
| case AFTER_NEWLINE: |
| case AFTER_NONWORD_CHARACTER: |
| case AFTER_WORD_CHARACTER: { |
| ASSERT_NOT_NULL(on_success()); |
| budget = on_success()->ComputeFirstCharacterSet(budget); |
| if (budget >= 0) { |
| set_first_character_set(on_success()->first_character_set()); |
| } |
| break; |
| } |
| } |
| } |
| return budget; |
| } |
| |
| |
| int ActionNode::ComputeFirstCharacterSet(int budget) { |
| if (type_ == POSITIVE_SUBMATCH_SUCCESS) return kComputeFirstCharacterSetFail; |
| budget--; |
| if (budget >= 0) { |
| ASSERT_NOT_NULL(on_success()); |
| budget = on_success()->ComputeFirstCharacterSet(budget); |
| if (budget >= 0) { |
| set_first_character_set(on_success()->first_character_set()); |
| } |
| } |
| return budget; |
| } |
| |
| |
| int BackReferenceNode::ComputeFirstCharacterSet(int budget) { |
| // We don't know anything about the first character of a backreference |
| // at this point. |
| // The potential first characters are the first characters of the capture, |
| // and the first characters of the on_success node, depending on whether the |
| // capture can be empty and whether it is known to be participating or known |
| // not to be. |
| return kComputeFirstCharacterSetFail; |
| } |
| |
| |
| int TextNode::ComputeFirstCharacterSet(int budget) { |
| budget--; |
| if (budget >= 0) { |
| ASSERT_NE(0, elements()->length()); |
| TextElement text = elements()->at(0); |
| if (text.type == TextElement::ATOM) { |
| RegExpAtom* atom = text.data.u_atom; |
| ASSERT_NE(0, atom->length()); |
| uc16 first_char = atom->data()[0]; |
| ZoneList<CharacterRange>* range = new ZoneList<CharacterRange>(1); |
| range->Add(CharacterRange(first_char, first_char)); |
| set_first_character_set(range); |
| } else { |
| ASSERT(text.type == TextElement::CHAR_CLASS); |
| RegExpCharacterClass* char_class = text.data.u_char_class; |
| ZoneList<CharacterRange>* ranges = char_class->ranges(); |
| // TODO(lrn): Canonicalize ranges when they are created |
| // instead of waiting until now. |
| CharacterRange::Canonicalize(ranges); |
| if (char_class->is_negated()) { |
| int length = ranges->length(); |
| int new_length = length + 1; |
| if (length > 0) { |
| if (ranges->at(0).from() == 0) new_length--; |
| if (ranges->at(length - 1).to() == String::kMaxUC16CharCode) { |
| new_length--; |
| } |
| } |
| ZoneList<CharacterRange>* negated_ranges = |
| new ZoneList<CharacterRange>(new_length); |
| CharacterRange::Negate(ranges, negated_ranges); |
| set_first_character_set(negated_ranges); |
| } else { |
| set_first_character_set(ranges); |
| } |
| } |
| } |
| return budget; |
| } |
| |
| |
| |
| // ------------------------------------------------------------------- |
| // Dispatch table construction |
| |
| |
| void DispatchTableConstructor::VisitEnd(EndNode* that) { |
| AddRange(CharacterRange::Everything()); |
| } |
| |
| |
| void DispatchTableConstructor::BuildTable(ChoiceNode* node) { |
| node->set_being_calculated(true); |
| ZoneList<GuardedAlternative>* alternatives = node->alternatives(); |
| for (int i = 0; i < alternatives->length(); i++) { |
| set_choice_index(i); |
| alternatives->at(i).node()->Accept(this); |
| } |
| node->set_being_calculated(false); |
| } |
| |
| |
| class AddDispatchRange { |
| public: |
| explicit AddDispatchRange(DispatchTableConstructor* constructor) |
| : constructor_(constructor) { } |
| void Call(uc32 from, DispatchTable::Entry entry); |
| private: |
| DispatchTableConstructor* constructor_; |
| }; |
| |
| |
| void AddDispatchRange::Call(uc32 from, DispatchTable::Entry entry) { |
| CharacterRange range(from, entry.to()); |
| constructor_->AddRange(range); |
| } |
| |
| |
| void DispatchTableConstructor::VisitChoice(ChoiceNode* node) { |
| if (node->being_calculated()) |
| return; |
| DispatchTable* table = node->GetTable(ignore_case_); |
| AddDispatchRange adder(this); |
| table->ForEach(&adder); |
| } |
| |
| |
| void DispatchTableConstructor::VisitBackReference(BackReferenceNode* that) { |
| // TODO(160): Find the node that we refer back to and propagate its start |
| // set back to here. For now we just accept anything. |
| AddRange(CharacterRange::Everything()); |
| } |
| |
| |
| void DispatchTableConstructor::VisitAssertion(AssertionNode* that) { |
| RegExpNode* target = that->on_success(); |
| target->Accept(this); |
| } |
| |
| |
| static int CompareRangeByFrom(const CharacterRange* a, |
| const CharacterRange* b) { |
| return Compare<uc16>(a->from(), b->from()); |
| } |
| |
| |
| void DispatchTableConstructor::AddInverse(ZoneList<CharacterRange>* ranges) { |
| ranges->Sort(CompareRangeByFrom); |
| uc16 last = 0; |
| for (int i = 0; i < ranges->length(); i++) { |
| CharacterRange range = ranges->at(i); |
| if (last < range.from()) |
| AddRange(CharacterRange(last, range.from() - 1)); |
| if (range.to() >= last) { |
| if (range.to() == String::kMaxUC16CharCode) { |
| return; |
| } else { |
| last = range.to() + 1; |
| } |
| } |
| } |
| AddRange(CharacterRange(last, String::kMaxUC16CharCode)); |
| } |
| |
| |
| void DispatchTableConstructor::VisitText(TextNode* that) { |
| TextElement elm = that->elements()->at(0); |
| switch (elm.type) { |
| case TextElement::ATOM: { |
| uc16 c = elm.data.u_atom->data()[0]; |
| AddRange(CharacterRange(c, c)); |
| break; |
| } |
| case TextElement::CHAR_CLASS: { |
| RegExpCharacterClass* tree = elm.data.u_char_class; |
| ZoneList<CharacterRange>* ranges = tree->ranges(); |
| if (tree->is_negated()) { |
| AddInverse(ranges); |
| } else { |
| for (int i = 0; i < ranges->length(); i++) |
| AddRange(ranges->at(i)); |
| } |
| break; |
| } |
| default: { |
| UNIMPLEMENTED(); |
| } |
| } |
| } |
| |
| |
| void DispatchTableConstructor::VisitAction(ActionNode* that) { |
| RegExpNode* target = that->on_success(); |
| target->Accept(this); |
| } |
| |
| |
| RegExpEngine::CompilationResult RegExpEngine::Compile(RegExpCompileData* data, |
| bool ignore_case, |
| bool is_multiline, |
| Handle<String> pattern, |
| bool is_ascii) { |
| if ((data->capture_count + 1) * 2 - 1 > RegExpMacroAssembler::kMaxRegister) { |
| return IrregexpRegExpTooBig(); |
| } |
| RegExpCompiler compiler(data->capture_count, ignore_case, is_ascii); |
| // Wrap the body of the regexp in capture #0. |
| RegExpNode* captured_body = RegExpCapture::ToNode(data->tree, |
| 0, |
| &compiler, |
| compiler.accept()); |
| RegExpNode* node = captured_body; |
| bool is_end_anchored = data->tree->IsAnchoredAtEnd(); |
| bool is_start_anchored = data->tree->IsAnchoredAtStart(); |
| int max_length = data->tree->max_match(); |
| if (!is_start_anchored) { |
| // Add a .*? at the beginning, outside the body capture, unless |
| // this expression is anchored at the beginning. |
| RegExpNode* loop_node = |
| RegExpQuantifier::ToNode(0, |
| RegExpTree::kInfinity, |
| false, |
| new RegExpCharacterClass('*'), |
| &compiler, |
| captured_body, |
| data->contains_anchor); |
| |
| if (data->contains_anchor) { |
| // Unroll loop once, to take care of the case that might start |
| // at the start of input. |
| ChoiceNode* first_step_node = new ChoiceNode(2); |
| first_step_node->AddAlternative(GuardedAlternative(captured_body)); |
| first_step_node->AddAlternative(GuardedAlternative( |
| new TextNode(new RegExpCharacterClass('*'), loop_node))); |
| node = first_step_node; |
| } else { |
| node = loop_node; |
| } |
| } |
| data->node = node; |
| Analysis analysis(ignore_case, is_ascii); |
| analysis.EnsureAnalyzed(node); |
| if (analysis.has_failed()) { |
| const char* error_message = analysis.error_message(); |
| return CompilationResult(error_message); |
| } |
| |
| NodeInfo info = *node->info(); |
| |
| // Create the correct assembler for the architecture. |
| #ifndef V8_INTERPRETED_REGEXP |
| // Native regexp implementation. |
| |
| NativeRegExpMacroAssembler::Mode mode = |
| is_ascii ? NativeRegExpMacroAssembler::ASCII |
| : NativeRegExpMacroAssembler::UC16; |
| |
| #if V8_TARGET_ARCH_IA32 |
| RegExpMacroAssemblerIA32 macro_assembler(mode, (data->capture_count + 1) * 2); |
| #elif V8_TARGET_ARCH_X64 |
| RegExpMacroAssemblerX64 macro_assembler(mode, (data->capture_count + 1) * 2); |
| #elif V8_TARGET_ARCH_ARM |
| RegExpMacroAssemblerARM macro_assembler(mode, (data->capture_count + 1) * 2); |
| #endif |
| |
| #else // V8_INTERPRETED_REGEXP |
| // Interpreted regexp implementation. |
| EmbeddedVector<byte, 1024> codes; |
| RegExpMacroAssemblerIrregexp macro_assembler(codes); |
| #endif // V8_INTERPRETED_REGEXP |
| |
| // Inserted here, instead of in Assembler, because it depends on information |
| // in the AST that isn't replicated in the Node structure. |
| static const int kMaxBacksearchLimit = 1024; |
| if (is_end_anchored && |
| !is_start_anchored && |
| max_length < kMaxBacksearchLimit) { |
| macro_assembler.SetCurrentPositionFromEnd(max_length); |
| } |
| |
| return compiler.Assemble(¯o_assembler, |
| node, |
| data->capture_count, |
| pattern); |
| } |
| |
| |
| int OffsetsVector::static_offsets_vector_[ |
| OffsetsVector::kStaticOffsetsVectorSize]; |
| |
| }} // namespace v8::internal |