1// Copyright 2012 the V8 project authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5#ifndef V8_REGEXP_ARM_REGEXP_MACRO_ASSEMBLER_ARM_H_
6#define V8_REGEXP_ARM_REGEXP_MACRO_ASSEMBLER_ARM_H_
7
8#include "src/codegen/macro-assembler.h"
9#include "src/regexp/regexp-macro-assembler.h"
10
11namespace v8 {
12namespace internal {
13
14class V8_EXPORT_PRIVATE RegExpMacroAssemblerARM
15    : public NativeRegExpMacroAssembler {
16 public:
17  RegExpMacroAssemblerARM(Isolate* isolate, Zone* zone, Mode mode,
18                          int registers_to_save);
19  ~RegExpMacroAssemblerARM() override;
20  void AbortedCodeGeneration() override;
21  int stack_limit_slack() override;
22  void AdvanceCurrentPosition(int by) override;
23  void AdvanceRegister(int reg, int by) override;
24  void Backtrack() override;
25  void Bind(Label* label) override;
26  void CheckAtStart(int cp_offset, Label* on_at_start) override;
27  void CheckCharacter(unsigned c, Label* on_equal) override;
28  void CheckCharacterAfterAnd(unsigned c, unsigned mask,
29                              Label* on_equal) override;
30  void CheckCharacterGT(base::uc16 limit, Label* on_greater) override;
31  void CheckCharacterLT(base::uc16 limit, Label* on_less) override;
32  // A "greedy loop" is a loop that is both greedy and with a simple
33  // body. It has a particularly simple implementation.
34  void CheckGreedyLoop(Label* on_tos_equals_current_position) override;
35  void CheckNotAtStart(int cp_offset, Label* on_not_at_start) override;
36  void CheckNotBackReference(int start_reg, bool read_backward,
37                             Label* on_no_match) override;
38  void CheckNotBackReferenceIgnoreCase(int start_reg, bool read_backward,
39                                       bool unicode,
40                                       Label* on_no_match) override;
41  void CheckNotCharacter(unsigned c, Label* on_not_equal) override;
42  void CheckNotCharacterAfterAnd(unsigned c, unsigned mask,
43                                 Label* on_not_equal) override;
44  void CheckNotCharacterAfterMinusAnd(base::uc16 c, base::uc16 minus,
45                                      base::uc16 mask,
46                                      Label* on_not_equal) override;
47  void CheckCharacterInRange(base::uc16 from, base::uc16 to,
48                             Label* on_in_range) override;
49  void CheckCharacterNotInRange(base::uc16 from, base::uc16 to,
50                                Label* on_not_in_range) override;
51  bool CheckCharacterInRangeArray(const ZoneList<CharacterRange>* ranges,
52                                  Label* on_in_range) override;
53  bool CheckCharacterNotInRangeArray(const ZoneList<CharacterRange>* ranges,
54                                     Label* on_not_in_range) override;
55  void CheckBitInTable(Handle<ByteArray> table, Label* on_bit_set) override;
56
57  // Checks whether the given offset from the current position is before
58  // the end of the string.
59  void CheckPosition(int cp_offset, Label* on_outside_input) override;
60  bool CheckSpecialCharacterClass(StandardCharacterSet type,
61                                  Label* on_no_match) override;
62  void Fail() override;
63  Handle<HeapObject> GetCode(Handle<String> source) override;
64  void GoTo(Label* label) override;
65  void IfRegisterGE(int reg, int comparand, Label* if_ge) override;
66  void IfRegisterLT(int reg, int comparand, Label* if_lt) override;
67  void IfRegisterEqPos(int reg, Label* if_eq) override;
68  IrregexpImplementation Implementation() override;
69  void LoadCurrentCharacterUnchecked(int cp_offset,
70                                     int character_count) override;
71  void PopCurrentPosition() override;
72  void PopRegister(int register_index) override;
73  void PushBacktrack(Label* label) override;
74  void PushCurrentPosition() override;
75  void PushRegister(int register_index,
76                    StackCheckFlag check_stack_limit) override;
77  void ReadCurrentPositionFromRegister(int reg) override;
78  void ReadStackPointerFromRegister(int reg) override;
79  void SetCurrentPositionFromEnd(int by) override;
80  void SetRegister(int register_index, int to) override;
81  bool Succeed() override;
82  void WriteCurrentPositionToRegister(int reg, int cp_offset) override;
83  void ClearRegisters(int reg_from, int reg_to) override;
84  void WriteStackPointerToRegister(int reg) override;
85
86  // Called from RegExp if the stack-guard is triggered.
87  // If the code object is relocated, the return address is fixed before
88  // returning.
89  // {raw_code} is an Address because this is called via ExternalReference.
90  static int CheckStackGuardState(Address* return_address, Address raw_code,
91                                  Address re_frame);
92
93 private:
94  // Offsets from frame_pointer() of function parameters and stored registers.
95  static const int kFramePointer = 0;
96
97  // Above the frame pointer - Stored registers and stack passed parameters.
98  static const int kStoredRegisters = kFramePointer;
99  // Return address (stored from link register, read into pc on return).
100  static const int kReturnAddress = kStoredRegisters + 8 * kPointerSize;
101  // Stack parameters placed by caller.
102  static const int kRegisterOutput = kReturnAddress + kPointerSize;
103  static const int kNumOutputRegisters = kRegisterOutput + kPointerSize;
104  static const int kDirectCall = kNumOutputRegisters + kPointerSize;
105  static const int kIsolate = kDirectCall + kPointerSize;
106
107  // Below the frame pointer.
108  // Register parameters stored by setup code.
109  static const int kInputEnd = kFramePointer - kPointerSize;
110  static const int kInputStart = kInputEnd - kPointerSize;
111  static const int kStartIndex = kInputStart - kPointerSize;
112  static const int kInputString = kStartIndex - kPointerSize;
113  // When adding local variables remember to push space for them in
114  // the frame in GetCode.
115  static const int kSuccessfulCaptures = kInputString - kPointerSize;
116  static const int kStringStartMinusOne = kSuccessfulCaptures - kPointerSize;
117  static const int kBacktrackCount = kStringStartMinusOne - kSystemPointerSize;
118  // Stores the initial value of the regexp stack pointer in a
119  // position-independent representation (in case the regexp stack grows and
120  // thus moves).
121  static const int kRegExpStackBasePointer =
122      kBacktrackCount - kSystemPointerSize;
123
124  // First register address. Following registers are below it on the stack.
125  static const int kRegisterZero = kRegExpStackBasePointer - kSystemPointerSize;
126
127  // Initial size of code buffer.
128  static const int kRegExpCodeSize = 1024;
129
130  static const int kBacktrackConstantPoolSize = 4;
131
132  // Check whether preemption has been requested.
133  void CheckPreemption();
134
135  // Check whether we are exceeding the stack limit on the backtrack stack.
136  void CheckStackLimit();
137
138  void CallCheckStackGuardState();
139  void CallIsCharacterInRangeArray(const ZoneList<CharacterRange>* ranges);
140
141  // The ebp-relative location of a regexp register.
142  MemOperand register_location(int register_index);
143
144  // Register holding the current input position as negative offset from
145  // the end of the string.
146  static constexpr Register current_input_offset() { return r6; }
147
148  // The register containing the current character after LoadCurrentCharacter.
149  static constexpr Register current_character() { return r7; }
150
151  // Register holding address of the end of the input string.
152  static constexpr Register end_of_input_address() { return r10; }
153
154  // Register holding the frame address. Local variables, parameters and
155  // regexp registers are addressed relative to this.
156  static constexpr Register frame_pointer() { return fp; }
157
158  // The register containing the backtrack stack top. Provides a meaningful
159  // name to the register.
160  static constexpr Register backtrack_stackpointer() { return r8; }
161
162  // Register holding pointer to the current code object.
163  static constexpr Register code_pointer() { return r5; }
164
165  // Byte size of chars in the string to match (decided by the Mode argument)
166  inline int char_size() const { return static_cast<int>(mode_); }
167
168  // Equivalent to a conditional branch to the label, unless the label
169  // is nullptr, in which case it is a conditional Backtrack.
170  void BranchOrBacktrack(Condition condition, Label* to);
171
172  // Call and return internally in the generated code in a way that
173  // is GC-safe (i.e., doesn't leave absolute code addresses on the stack)
174  inline void SafeCall(Label* to, Condition cond = al);
175  inline void SafeReturn();
176  inline void SafeCallTarget(Label* name);
177
178  // Pushes the value of a register on the backtrack stack. Decrements the
179  // stack pointer by a word size and stores the register's value there.
180  inline void Push(Register source);
181
182  // Pops a value from the backtrack stack. Reads the word at the stack pointer
183  // and increments it by a word size.
184  inline void Pop(Register target);
185
186  void LoadRegExpStackPointerFromMemory(Register dst);
187  void StoreRegExpStackPointerToMemory(Register src, Register scratch);
188  void PushRegExpBasePointer(Register stack_pointer, Register scratch);
189  void PopRegExpBasePointer(Register stack_pointer_out, Register scratch);
190
191  Isolate* isolate() const { return masm_->isolate(); }
192
193  const std::unique_ptr<MacroAssembler> masm_;
194  const NoRootArrayScope no_root_array_scope_;
195
196  // Which mode to generate code for (Latin1 or UC16).
197  const Mode mode_;
198
199  // One greater than maximal register index actually used.
200  int num_registers_;
201
202  // Number of registers to output at the end (the saved registers
203  // are always 0..num_saved_registers_-1)
204  const int num_saved_registers_;
205
206  // Labels used internally.
207  Label entry_label_;
208  Label start_label_;
209  Label success_label_;
210  Label backtrack_label_;
211  Label exit_label_;
212  Label check_preempt_label_;
213  Label stack_overflow_label_;
214  Label fallback_label_;
215};
216
217}  // namespace internal
218}  // namespace v8
219
220#endif  // V8_REGEXP_ARM_REGEXP_MACRO_ASSEMBLER_ARM_H_
221