// Copyright 2012 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef V8_REGEXP_REGEXP_MACRO_ASSEMBLER_H_
#define V8_REGEXP_REGEXP_MACRO_ASSEMBLER_H_
#include "irregexp/imported/regexp-ast.h"
#include "irregexp/imported/regexp.h"
#include "irregexp/RegExpShim.h"
namespace v8 {
namespace internal {
class ByteArray;
class JSRegExp;
class Label;
class String;
static const base::uc32 kLeadSurrogateStart = 0xd800;
static const base::uc32 kLeadSurrogateEnd = 0xdbff;
static const base::uc32 kTrailSurrogateStart = 0xdc00;
static const base::uc32 kTrailSurrogateEnd = 0xdfff;
static const base::uc32 kNonBmpStart = 0x10000;
static const base::uc32 kNonBmpEnd = 0x10ffff;
class RegExpMacroAssembler {
public:
// The implementation must be able to handle at least:
static constexpr
int kMaxRegisterCount = (1 << 16);
static constexpr
int kMaxRegister = kMaxRegisterCount - 1;
static constexpr
int kMaxCaptures = (kMaxRegister - 1) / 2;
static constexpr
int kMaxCPOffset = (1 << 15) - 1;
static constexpr
int kMinCPOffset = -(1 << 15);
static constexpr
int kTableSizeBits = 7;
static constexpr
int kTableSize = 1 << kTableSizeBits;
static constexpr
int kTableMask = kTableSize - 1;
static constexpr
int kUseCharactersValue = -1;
RegExpMacroAssembler(Isolate* isolate, Zone* zone);
virtual ~RegExpMacroAssembler() =
default;
virtual Handle<HeapObject> GetCode(Handle<String> source,
RegExpFlags flags) = 0;
// This function is called when code generation is aborted, so that
// the assembler could clean up internal data structures.
virtual void AbortedCodeGeneration() {}
// 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_slot_count() = 0;
virtual bool CanReadUnaligned()
const = 0;
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;
// 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(base::uc16 limit, Label* on_greater) = 0;
virtual void CheckCharacterLT(base::uc16 limit, Label* on_less) = 0;
virtual void CheckGreedyLoop(Label* on_tos_equals_current_position) = 0;
virtual void CheckAtStart(
int cp_offset, Label* on_at_start) = 0;
virtual void CheckNotAtStart(
int cp_offset, Label* on_not_at_start) = 0;
virtual void CheckNotBackReference(
int start_reg,
bool read_backward,
Label* on_no_match) = 0;
virtual void CheckNotBackReferenceIgnoreCase(
int start_reg,
bool read_backward,
bool unicode,
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 nullptr 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 and with the given
// constant and then check for a match with c.
virtual void CheckNotCharacterAfterMinusAnd(base::uc16 c, base::uc16 minus,
base::uc16 and_with,
Label* on_not_equal) = 0;
virtual void CheckCharacterInRange(base::uc16 from,
base::uc16 to,
// Both inclusive.
Label* on_in_range) = 0;
virtual void CheckCharacterNotInRange(base::uc16 from,
base::uc16 to,
// Both inclusive.
Label* on_not_in_range) = 0;
// Returns true if the check was emitted, false otherwise.
virtual bool CheckCharacterInRangeArray(
const ZoneList<CharacterRange>* ranges, Label* on_in_range) = 0;
virtual bool CheckCharacterNotInRangeArray(
const ZoneList<CharacterRange>* ranges, Label* on_not_in_range) = 0;
// The current character (modulus the kTableSize) is looked up in the byte
// array, and if the found byte is non-zero, we jump to the on_bit_set label.
virtual void CheckBitInTable(Handle<ByteArray> table, Label* on_bit_set) = 0;
virtual void SkipUntilBitInTable(
int cp_offset, Handle<ByteArray> table,
Handle<ByteArray> nibble_table,
int advance_by) = 0;
virtual bool SkipUntilBitInTableUseSimd(
int advance_by) {
return false; }
// 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);
// 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 CheckSpecialClassRanges(StandardCharacterSet type,
Label* on_no_match) {
return false;
}
// Control-flow integrity:
// Define a jump target and bind a label.
virtual void BindJumpTarget(Label* label) { Bind(label); }
virtual void Fail() = 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 nullptr.
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 nullptr.
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;
V8_EXPORT_PRIVATE
void LoadCurrentCharacter(
int cp_offset, Label* on_end_of_input,
bool check_bounds =
true,
int characters = 1,
int eats_at_least = kUseCharactersValue);
virtual void LoadCurrentCharacterImpl(
int cp_offset, Label* on_end_of_input,
bool check_bounds,
int characters,
int eats_at_least) = 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;
enum StackCheckFlag { kNoStackLimitCheck =
false, kCheckStackLimit =
true };
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;
// Return whether the matching (with a global regexp) will be restarted.
virtual bool 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;
// Check that we are not in the middle of a surrogate pair.
void CheckNotInSurrogatePair(
int cp_offset, Label* on_failure);
#define IMPLEMENTATIONS_LIST(V) \
V(IA32) \
V(ARM) \
V(ARM64) \
V(MIPS) \
V(LOONG64) \
V(RISCV) \
V(RISCV32) \
V(S390) \
V(PPC) \
V(X64) \
V(Bytecode)
enum IrregexpImplementation {
#define V(Name) k
##Name
##Implementation,
IMPLEMENTATIONS_LIST(V)
#undef V
};
inline const char* ImplementationToString(IrregexpImplementation impl) {
static const char*
const kNames[] = {
#define V(Name)
#Name,
IMPLEMENTATIONS_LIST(V)
#undef V
};
return kNames[impl];
}
#undef IMPLEMENTATIONS_LIST
virtual IrregexpImplementation Implementation() = 0;
// Compare two-byte strings case insensitively.
//
// Called from generated code.
static int CaseInsensitiveCompareNonUnicode(Address byte_offset1,
Address byte_offset2,
size_t byte_length,
Isolate* isolate);
static int CaseInsensitiveCompareUnicode(Address byte_offset1,
Address byte_offset2,
size_t byte_length,
Isolate* isolate);
// `raw_byte_array` is a ByteArray containing a set of character ranges,
// where ranges are encoded as uint16_t elements:
//
// [from0, to0, from1, to1, ..., fromN, toN], or
// [from0, to0, from1, to1, ..., fromN] (open-ended last interval).
//
// fromN is inclusive, toN is exclusive. Returns zero if not in a range,
// non-zero otherwise.
//
// Called from generated code.
static uint32_t IsCharacterInRangeArray(uint32_t current_char,
Address raw_byte_array);
// Controls the generation of large inlined constants in the code.
void set_slow_safe(
bool ssc) { slow_safe_compiler_ = ssc; }
bool slow_safe()
const {
return slow_safe_compiler_; }
// Controls after how many backtracks irregexp should abort execution. If it
// can fall back to the experimental engine (see `set_can_fallback`), it will
// return the appropriate error code, otherwise it will return the number of
// matches found so far (perhaps none).
void set_backtrack_limit(uint32_t backtrack_limit) {
backtrack_limit_ = backtrack_limit;
}
// Set whether or not irregexp can fall back to the experimental engine on
// excessive backtracking. The number of backtracks considered excessive can
// be controlled with set_backtrack_limit.
void set_can_fallback(
bool val) { can_fallback_ = val; }
enum GlobalMode {
NOT_GLOBAL,
GLOBAL_NO_ZERO_LENGTH_CHECK,
GLOBAL,
GLOBAL_UNICODE
};
// Set whether the regular expression has the global flag. Exiting due to
// a failure in a global regexp may still mean success overall.
inline void set_global_mode(GlobalMode mode) { global_mode_ = mode; }
inline bool global()
const {
return global_mode_ != NOT_GLOBAL; }
inline bool global_with_zero_length_check()
const {
return global_mode_ == GLOBAL || global_mode_ == GLOBAL_UNICODE;
}
inline bool global_unicode()
const {
return global_mode_ == GLOBAL_UNICODE; }
Isolate* isolate()
const {
return isolate_; }
Zone* zone()
const {
return zone_; }
protected:
bool has_backtrack_limit()
const;
uint32_t backtrack_limit()
const {
return backtrack_limit_; }
bool can_fallback()
const {
return can_fallback_; }
private:
bool slow_safe_compiler_;
uint32_t backtrack_limit_;
bool can_fallback_ =
false;
GlobalMode global_mode_;
Isolate*
const isolate_;
Zone*
const zone_;
};
class NativeRegExpMacroAssembler:
public RegExpMacroAssembler {
public:
// Type of input string to generate code for.
enum Mode { LATIN1 = 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.
// FALLBACK_TO_EXPERIMENTAL: Execute the regexp on this subject using the
// experimental engine instead.
enum Result {
FAILURE = RegExp::kInternalRegExpFailure,
SUCCESS = RegExp::kInternalRegExpSuccess,
EXCEPTION = RegExp::kInternalRegExpException,
RETRY = RegExp::kInternalRegExpRetry,
FALLBACK_TO_EXPERIMENTAL = RegExp::kInternalRegExpFallbackToExperimental,
SMALLEST_REGEXP_RESULT = RegExp::kInternalRegExpSmallestResult,
};
NativeRegExpMacroAssembler(Isolate* isolate, Zone* zone)
: RegExpMacroAssembler(isolate, zone), range_array_cache_(zone) {}
~NativeRegExpMacroAssembler() override =
default;
// Returns a {Result} sentinel, or the number of successful matches.
static int Match(DirectHandle<IrRegExpData> regexp_data,
DirectHandle<String> subject,
int* offsets_vector,
int offsets_vector_length,
int previous_index,
Isolate* isolate);
V8_EXPORT_PRIVATE
static int ExecuteForTesting(
Tagged<String> input,
int start_offset,
const uint8_t* input_start,
const uint8_t* input_end,
int* output,
int output_size, Isolate* isolate,
Tagged<JSRegExp> regexp);
bool CanReadUnaligned()
const override;
void LoadCurrentCharacterImpl(
int cp_offset, Label* on_end_of_input,
bool check_bounds,
int characters,
int eats_at_least) override;
// Load a number of characters at the given offset from the
// current position, into the current-character register.
virtual void LoadCurrentCharacterUnchecked(
int cp_offset,
int character_count) = 0;
// Called from RegExp if the backtrack stack limit is hit. Tries to expand
// the stack. Returns the new stack-pointer if successful, or returns 0 if
// unable to grow the stack.
// This function must not trigger a garbage collection.
//
// Called from generated code.
static Address GrowStack(Isolate* isolate);
// Called from generated code.
static int CheckStackGuardState(Isolate* isolate,
int start_index,
RegExp::CallOrigin call_origin,
Address* return_address,
Tagged<InstructionStream> re_code,
Address* subject,
const uint8_t** input_start,
const uint8_t** input_end, uintptr_t gap);
static Address word_character_map_address() {
return reinterpret_cast<Address>(&word_character_map[0]);
}
protected:
// Byte map of one byte 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 uint8_t word_character_map[256];
Handle<ByteArray> GetOrAddRangeArray(
const ZoneList<CharacterRange>* ranges);
private:
// Returns a {Result} sentinel, or the number of successful matches.
static int Execute(Tagged<String> input,
int start_offset,
const uint8_t* input_start,
const uint8_t* input_end,
int* output,
int output_size, Isolate* isolate,
Tagged<IrRegExpData> regexp_data);
ZoneUnorderedMap<uint32_t, IndirectHandle<FixedUInt16Array>>
range_array_cache_;
};
}
// namespace internal
}
// namespace v8
#endif // V8_REGEXP_REGEXP_MACRO_ASSEMBLER_H_
