// Copyright 2008 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
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#ifndef V8_REGEXP_MACRO_ASSEMBLER_H_
#define V8_REGEXP_MACRO_ASSEMBLER_H_
#include "ast.h"
namespace v8 {
namespace internal {
struct DisjunctDecisionRow {
RegExpCharacterClass cc;
Label* on_match;
};
class RegExpMacroAssembler {
public:
// The implementation must be able to handle at least:
static const int kMaxRegister = (1 << 16) - 1;
static const int kMaxCPOffset = (1 << 15) - 1;
static const int kMinCPOffset = -(1 << 15);
enum IrregexpImplementation {
kIA32Implementation,
kARMImplementation,
kMIPSImplementation,
kX64Implementation,
kBytecodeImplementation
};
enum StackCheckFlag {
kNoStackLimitCheck = false,
kCheckStackLimit = true
};
RegExpMacroAssembler();
virtual ~RegExpMacroAssembler();
// The maximal number of pushes between stack checks. Users must supply
// kCheckStackLimit flag to push operations (instead of kNoStackLimitCheck)
// at least once for every stack_limit() pushes that are executed.
virtual int stack_limit_slack() = 0;
virtual bool CanReadUnaligned();
virtual void AdvanceCurrentPosition(int by) = 0; // Signed cp change.
virtual void AdvanceRegister(int reg, int by) = 0; // r[reg] += by.
// Continues execution from the position pushed on the top of the backtrack
// stack by an earlier PushBacktrack(Label*).
virtual void Backtrack() = 0;
virtual void Bind(Label* label) = 0;
virtual void CheckAtStart(Label* on_at_start) = 0;
// Dispatch after looking the current character up in a 2-bits-per-entry
// map. The destinations vector has up to 4 labels.
virtual void CheckCharacter(unsigned c, Label* on_equal) = 0;
// Bitwise and the current character with the given constant and then
// check for a match with c.
virtual void CheckCharacterAfterAnd(unsigned c,
unsigned and_with,
Label* on_equal) = 0;
virtual void CheckCharacterGT(uc16 limit, Label* on_greater) = 0;
virtual void CheckCharacterLT(uc16 limit, Label* on_less) = 0;
// Check the current character for a match with a literal string. If we
// fail to match then goto the on_failure label. If check_eos is set then
// the end of input always fails. If check_eos is clear then it is the
// caller's responsibility to ensure that the end of string is not hit.
// If the label is NULL then we should pop a backtrack address off
// the stack and go to that.
virtual void CheckCharacters(
Vector<const uc16> str,
int cp_offset,
Label* on_failure,
bool check_eos) = 0;
virtual void CheckGreedyLoop(Label* on_tos_equals_current_position) = 0;
virtual void CheckNotAtStart(Label* on_not_at_start) = 0;
virtual void CheckNotBackReference(int start_reg, Label* on_no_match) = 0;
virtual void CheckNotBackReferenceIgnoreCase(int start_reg,
Label* on_no_match) = 0;
// Check the current character for a match with a literal character. If we
// fail to match then goto the on_failure label. End of input always
// matches. If the label is NULL then we should pop a backtrack address off
// the stack and go to that.
virtual void CheckNotCharacter(unsigned c, Label* on_not_equal) = 0;
virtual void CheckNotCharacterAfterAnd(unsigned c,
unsigned and_with,
Label* on_not_equal) = 0;
// Subtract a constant from the current character, then or with the given
// constant and then check for a match with c.
virtual void CheckNotCharacterAfterMinusAnd(uc16 c,
uc16 minus,
uc16 and_with,
Label* on_not_equal) = 0;
virtual void CheckNotRegistersEqual(int reg1,
int reg2,
Label* on_not_equal) = 0;
// Checks whether the given offset from the current position is before
// the end of the string. May overwrite the current character.
virtual void CheckPosition(int cp_offset, Label* on_outside_input) {
LoadCurrentCharacter(cp_offset, on_outside_input, true);
}
// Check whether a standard/default character class matches the current
// character. Returns false if the type of special character class does
// not have custom support.
// May clobber the current loaded character.
virtual bool CheckSpecialCharacterClass(uc16 type,
Label* on_no_match) {
return false;
}
virtual void Fail() = 0;
virtual Handle<HeapObject> GetCode(Handle<String> source) = 0;
virtual void GoTo(Label* label) = 0;
// Check whether a register is >= a given constant and go to a label if it
// is. Backtracks instead if the label is NULL.
virtual void IfRegisterGE(int reg, int comparand, Label* if_ge) = 0;
// Check whether a register is < a given constant and go to a label if it is.
// Backtracks instead if the label is NULL.
virtual void IfRegisterLT(int reg, int comparand, Label* if_lt) = 0;
// Check whether a register is == to the current position and go to a
// label if it is.
virtual void IfRegisterEqPos(int reg, Label* if_eq) = 0;
virtual IrregexpImplementation Implementation() = 0;
virtual void LoadCurrentCharacter(int cp_offset,
Label* on_end_of_input,
bool check_bounds = true,
int characters = 1) = 0;
virtual void PopCurrentPosition() = 0;
virtual void PopRegister(int register_index) = 0;
// Pushes the label on the backtrack stack, so that a following Backtrack
// will go to this label. Always checks the backtrack stack limit.
virtual void PushBacktrack(Label* label) = 0;
virtual void PushCurrentPosition() = 0;
virtual void PushRegister(int register_index,
StackCheckFlag check_stack_limit) = 0;
virtual void ReadCurrentPositionFromRegister(int reg) = 0;
virtual void ReadStackPointerFromRegister(int reg) = 0;
virtual void SetCurrentPositionFromEnd(int by) = 0;
virtual void SetRegister(int register_index, int to) = 0;
virtual void Succeed() = 0;
virtual void WriteCurrentPositionToRegister(int reg, int cp_offset) = 0;
virtual void ClearRegisters(int reg_from, int reg_to) = 0;
virtual void WriteStackPointerToRegister(int reg) = 0;
// Controls the generation of large inlined constants in the code.
void set_slow_safe(bool ssc) { slow_safe_compiler_ = ssc; }
bool slow_safe() { return slow_safe_compiler_; }
private:
bool slow_safe_compiler_;
};
#ifndef V8_INTERPRETED_REGEXP // Avoid compiling unused code.
class NativeRegExpMacroAssembler: public RegExpMacroAssembler {
public:
// Type of input string to generate code for.
enum Mode { ASCII = 1, UC16 = 2 };
// Result of calling generated native RegExp code.
// RETRY: Something significant changed during execution, and the matching
// should be retried from scratch.
// EXCEPTION: Something failed during execution. If no exception has been
// thrown, it's an internal out-of-memory, and the caller should
// throw the exception.
// FAILURE: Matching failed.
// SUCCESS: Matching succeeded, and the output array has been filled with
// capture positions.
enum Result { RETRY = -2, EXCEPTION = -1, FAILURE = 0, SUCCESS = 1 };
NativeRegExpMacroAssembler();
virtual ~NativeRegExpMacroAssembler();
virtual bool CanReadUnaligned();
static Result Match(Handle<Code> regexp,
Handle<String> subject,
int* offsets_vector,
int offsets_vector_length,
int previous_index,
Isolate* isolate);
// Compares two-byte strings case insensitively.
// Called from generated RegExp code.
static int CaseInsensitiveCompareUC16(Address byte_offset1,
Address byte_offset2,
size_t byte_length,
Isolate* isolate);
// Called from RegExp if the backtrack stack limit is hit.
// Tries to expand the stack. Returns the new stack-pointer if
// successful, and updates the stack_top address, or returns 0 if unable
// to grow the stack.
// This function must not trigger a garbage collection.
static Address GrowStack(Address stack_pointer, Address* stack_top,
Isolate* isolate);
static const byte* StringCharacterPosition(String* subject, int start_index);
// Byte map of ASCII characters with a 0xff if the character is a word
// character (digit, letter or underscore) and 0x00 otherwise.
// Used by generated RegExp code.
static const byte word_character_map[128];
static Address word_character_map_address() {
return const_cast<Address>(&word_character_map[0]);
}
static Result Execute(Code* code,
String* input,
int start_offset,
const byte* input_start,
const byte* input_end,
int* output,
Isolate* isolate);
};
#endif // V8_INTERPRETED_REGEXP
} } // namespace v8::internal
#endif // V8_REGEXP_MACRO_ASSEMBLER_H_