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// Copyright (c) 2014, the Dart project authors. Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.
#ifndef RUNTIME_VM_REGEXP_ASSEMBLER_H_
#define RUNTIME_VM_REGEXP_ASSEMBLER_H_
#include "vm/compiler/assembler/assembler.h"
#include "vm/compiler/backend/il.h"
#include "vm/object.h"
namespace dart {
// Utility function for the DotPrinter
void PrintUtf16(uint16_t c);
/// Convenience wrapper around a BlockEntryInstr pointer.
class BlockLabel : public ValueObject {
// Used by the IR assembler.
public:
BlockLabel();
JoinEntryInstr* block() const { return block_; }
bool IsBound() const { return is_bound_; }
void SetBound(intptr_t block_id) {
ASSERT(!is_bound_);
block_->set_block_id(block_id);
is_bound_ = true;
}
bool IsLinked() const { return !is_bound_ && is_linked_; }
void SetLinked() { is_linked_ = true; }
intptr_t Position() const {
ASSERT(IsBound());
return block_->block_id();
}
private:
JoinEntryInstr* block_;
bool is_bound_;
bool is_linked_;
// Used by the bytecode assembler.
public:
~BlockLabel() { ASSERT(!is_linked()); }
intptr_t pos() const { return pos_; }
bool is_bound() const { return IsBound(); }
bool is_linked() const { return IsLinked(); }
void Unuse() {
pos_ = 0;
is_bound_ = false;
is_linked_ = false;
}
void bind_to(intptr_t pos) {
pos_ = pos;
is_bound_ = true;
is_linked_ = false;
ASSERT(is_bound());
}
void link_to(intptr_t pos) {
pos_ = pos;
is_bound_ = false;
is_linked_ = true;
ASSERT(is_linked());
}
private:
intptr_t pos_;
};
class RegExpMacroAssembler : public ZoneAllocated {
public:
// The implementation must be able to handle at least:
static const intptr_t kMaxRegister = (1 << 16) - 1;
static const intptr_t kMaxCPOffset = (1 << 15) - 1;
static const intptr_t kMinCPOffset = -(1 << 15);
static const intptr_t kTableSizeBits = 7;
static const intptr_t kTableSize = 1 << kTableSizeBits;
static const intptr_t kTableMask = kTableSize - 1;
enum {
kParamRegExpIndex = 0,
kParamStringIndex,
kParamStartOffsetIndex,
kParamCount
};
enum IrregexpImplementation { kBytecodeImplementation, kIRImplementation };
explicit RegExpMacroAssembler(Zone* zone);
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 intptr_t stack_limit_slack() = 0;
virtual bool CanReadUnaligned() = 0;
virtual void AdvanceCurrentPosition(intptr_t by) = 0; // Signed cp change.
virtual void AdvanceRegister(intptr_t reg, intptr_t by) = 0; // r[reg] += by.
// Continues execution from the position pushed on the top of the backtrack
// stack by an earlier PushBacktrack(BlockLabel*).
virtual void Backtrack() = 0;
virtual void BindBlock(BlockLabel* label) = 0;
virtual void CheckAtStart(BlockLabel* 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, BlockLabel* 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,
BlockLabel* on_equal) = 0;
virtual void CheckCharacterGT(uint16_t limit, BlockLabel* on_greater) = 0;
virtual void CheckCharacterLT(uint16_t limit, BlockLabel* on_less) = 0;
virtual void CheckGreedyLoop(BlockLabel* on_tos_equals_current_position) = 0;
virtual void CheckNotAtStart(BlockLabel* on_not_at_start) = 0;
virtual void CheckNotBackReference(intptr_t start_reg,
BlockLabel* on_no_match) = 0;
virtual void CheckNotBackReferenceIgnoreCase(intptr_t start_reg,
BlockLabel* 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, BlockLabel* on_not_equal) = 0;
virtual void CheckNotCharacterAfterAnd(unsigned c,
unsigned and_with,
BlockLabel* 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(uint16_t c,
uint16_t minus,
uint16_t and_with,
BlockLabel* on_not_equal) = 0;
virtual void CheckCharacterInRange(uint16_t from,
uint16_t to, // Both inclusive.
BlockLabel* on_in_range) = 0;
virtual void CheckCharacterNotInRange(uint16_t from,
uint16_t to, // Both inclusive.
BlockLabel* 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(const TypedData& table,
BlockLabel* on_bit_set) = 0;
// Checks for preemption and serves as an OSR entry.
virtual void CheckPreemption(bool is_backtrack) {}
// Checks whether the given offset from the current position is before
// the end of the string. May overwrite the current character.
virtual void CheckPosition(intptr_t cp_offset, BlockLabel* 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(uint16_t type,
BlockLabel* on_no_match) {
return false;
}
virtual void Fail() = 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(intptr_t reg,
intptr_t comparand,
BlockLabel* 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(intptr_t reg,
intptr_t comparand,
BlockLabel* if_lt) = 0;
// Check whether a register is == to the current position and go to a
// label if it is.
virtual void IfRegisterEqPos(intptr_t reg, BlockLabel* if_eq) = 0;
virtual IrregexpImplementation Implementation() = 0;
// The assembler is closed, iff there is no current instruction assigned.
virtual bool IsClosed() const = 0;
// Jump to the target label without setting it as the current instruction.
virtual void GoTo(BlockLabel* to) = 0;
virtual void LoadCurrentCharacter(intptr_t cp_offset,
BlockLabel* on_end_of_input,
bool check_bounds = true,
intptr_t characters = 1) = 0;
virtual void PopCurrentPosition() = 0;
virtual void PopRegister(intptr_t register_index) = 0;
// Prints string within the generated code. Used for debugging.
virtual void Print(const char* str) = 0;
// Prints all emitted blocks.
virtual void PrintBlocks() = 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(BlockLabel* label) = 0;
virtual void PushCurrentPosition() = 0;
virtual void PushRegister(intptr_t register_index) = 0;
virtual void ReadCurrentPositionFromRegister(intptr_t reg) = 0;
virtual void ReadStackPointerFromRegister(intptr_t reg) = 0;
virtual void SetCurrentPositionFromEnd(intptr_t by) = 0;
virtual void SetRegister(intptr_t register_index, intptr_t to) = 0;
// Return whether the matching (with a global regexp) will be restarted.
virtual bool Succeed() = 0;
virtual void WriteCurrentPositionToRegister(intptr_t reg,
intptr_t cp_offset) = 0;
virtual void ClearRegisters(intptr_t reg_from, intptr_t reg_to) = 0;
virtual void WriteStackPointerToRegister(intptr_t 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_; }
enum GlobalMode { NOT_GLOBAL, GLOBAL, GLOBAL_NO_ZERO_LENGTH_CHECK };
// 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() { return global_mode_ != NOT_GLOBAL; }
inline bool global_with_zero_length_check() { return global_mode_ == GLOBAL; }
Zone* zone() const { return zone_; }
private:
bool slow_safe_compiler_;
bool global_mode_;
Zone* zone_;
};
} // namespace dart
#endif // RUNTIME_VM_REGEXP_ASSEMBLER_H_