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_IA32_REGEXP_MACRO_ASSEMBLER_IA32_H_
6#define V8_REGEXP_IA32_REGEXP_MACRO_ASSEMBLER_IA32_H_
7
8#include "src/base/strings.h"
9#include "src/codegen/ia32/assembler-ia32.h"
10#include "src/codegen/macro-assembler.h"
11#include "src/regexp/regexp-macro-assembler.h"
12
13namespace v8 {
14namespace internal {
15
16class V8_EXPORT_PRIVATE RegExpMacroAssemblerIA32
17    : public NativeRegExpMacroAssembler {
18 public:
19  RegExpMacroAssemblerIA32(Isolate* isolate, Zone* zone, Mode mode,
20                           int registers_to_save);
21  ~RegExpMacroAssemblerIA32() override;
22  int stack_limit_slack() override;
23  void AdvanceCurrentPosition(int by) override;
24  void AdvanceRegister(int reg, int by) override;
25  void Backtrack() override;
26  void Bind(Label* label) override;
27  void CheckAtStart(int cp_offset, Label* on_at_start) override;
28  void CheckCharacter(uint32_t c, Label* on_equal) override;
29  void CheckCharacterAfterAnd(uint32_t c, uint32_t mask,
30                              Label* on_equal) override;
31  void CheckCharacterGT(base::uc16 limit, Label* on_greater) override;
32  void CheckCharacterLT(base::uc16 limit, Label* on_less) override;
33  // A "greedy loop" is a loop that is both greedy and with a simple
34  // body. It has a particularly simple implementation.
35  void CheckGreedyLoop(Label* on_tos_equals_current_position) override;
36  void CheckNotAtStart(int cp_offset, Label* on_not_at_start) override;
37  void CheckNotBackReference(int start_reg, bool read_backward,
38                             Label* on_no_match) override;
39  void CheckNotBackReferenceIgnoreCase(int start_reg, bool read_backward,
40                                       bool unicode,
41                                       Label* on_no_match) override;
42  void CheckNotCharacter(uint32_t c, Label* on_not_equal) override;
43  void CheckNotCharacterAfterAnd(uint32_t c, uint32_t mask,
44                                 Label* on_not_equal) override;
45  void CheckNotCharacterAfterMinusAnd(base::uc16 c, base::uc16 minus,
46                                      base::uc16 mask,
47                                      Label* on_not_equal) override;
48  void CheckCharacterInRange(base::uc16 from, base::uc16 to,
49                             Label* on_in_range) override;
50  void CheckCharacterNotInRange(base::uc16 from, base::uc16 to,
51                                Label* on_not_in_range) override;
52  bool CheckCharacterInRangeArray(const ZoneList<CharacterRange>* ranges,
53                                  Label* on_in_range) override;
54  bool CheckCharacterNotInRangeArray(const ZoneList<CharacterRange>* ranges,
55                                     Label* on_not_in_range) override;
56  void CheckBitInTable(Handle<ByteArray> table, Label* on_bit_set) override;
57
58  // Checks whether the given offset from the current position is before
59  // the end of the string.
60  void CheckPosition(int cp_offset, Label* on_outside_input) override;
61  bool CheckSpecialCharacterClass(StandardCharacterSet type,
62                                  Label* on_no_match) override;
63  void Fail() override;
64  Handle<HeapObject> GetCode(Handle<String> source) override;
65  void GoTo(Label* label) override;
66  void IfRegisterGE(int reg, int comparand, Label* if_ge) override;
67  void IfRegisterLT(int reg, int comparand, Label* if_lt) override;
68  void IfRegisterEqPos(int reg, Label* if_eq) override;
69  IrregexpImplementation Implementation() override;
70  void LoadCurrentCharacterUnchecked(int cp_offset,
71                                     int character_count) override;
72  void PopCurrentPosition() override;
73  void PopRegister(int register_index) override;
74  void PushBacktrack(Label* label) override;
75  void PushCurrentPosition() override;
76  void PushRegister(int register_index,
77                    StackCheckFlag check_stack_limit) override;
78  void ReadCurrentPositionFromRegister(int reg) override;
79  void ReadStackPointerFromRegister(int reg) override;
80  void SetCurrentPositionFromEnd(int by) override;
81  void SetRegister(int register_index, int to) override;
82  bool Succeed() override;
83  void WriteCurrentPositionToRegister(int reg, int cp_offset) override;
84  void ClearRegisters(int reg_from, int reg_to) override;
85  void WriteStackPointerToRegister(int reg) override;
86
87  // Called from RegExp if the stack-guard is triggered.
88  // If the code object is relocated, the return address is fixed before
89  // returning.
90  // {raw_code} is an Address because this is called via ExternalReference.
91  static int CheckStackGuardState(Address* return_address, Address raw_code,
92                                  Address re_frame);
93
94 private:
95  Operand StaticVariable(const ExternalReference& ext);
96  // Offsets from ebp of function parameters and stored registers.
97  static const int kFramePointer = 0;
98  // Above the frame pointer - function parameters and return address.
99  static const int kReturn_eip = kFramePointer + kSystemPointerSize;
100  static const int kFrameAlign = kReturn_eip + kSystemPointerSize;
101  // Parameters.
102  static const int kInputString = kFrameAlign;
103  static const int kStartIndex = kInputString + kSystemPointerSize;
104  static const int kInputStart = kStartIndex + kSystemPointerSize;
105  static const int kInputEnd = kInputStart + kSystemPointerSize;
106  static const int kRegisterOutput = kInputEnd + kSystemPointerSize;
107  // For the case of global regular expression, we have room to store at least
108  // one set of capture results.  For the case of non-global regexp, we ignore
109  // this value.
110  static const int kNumOutputRegisters = kRegisterOutput + kSystemPointerSize;
111  static const int kDirectCall = kNumOutputRegisters + kSystemPointerSize;
112  static const int kIsolate = kDirectCall + kSystemPointerSize;
113  // Below the frame pointer - local stack variables.
114  // When adding local variables remember to push space for them in
115  // the frame in GetCode.
116  static const int kBackup_esi = kFramePointer - kSystemPointerSize;
117  static const int kBackup_edi = kBackup_esi - kSystemPointerSize;
118  static const int kBackup_ebx = kBackup_edi - kSystemPointerSize;
119  static const int kLastCalleeSaveRegister = kBackup_ebx;
120
121  static const int kSuccessfulCaptures =
122      kLastCalleeSaveRegister - kSystemPointerSize;
123  static const int kStringStartMinusOne =
124      kSuccessfulCaptures - kSystemPointerSize;
125  static const int kBacktrackCount = kStringStartMinusOne - kSystemPointerSize;
126  // Stores the initial value of the regexp stack pointer in a
127  // position-independent representation (in case the regexp stack grows and
128  // thus moves).
129  static const int kRegExpStackBasePointer =
130      kBacktrackCount - kSystemPointerSize;
131  // First register address. Following registers are below it on the stack.
132  static const int kRegisterZero = kRegExpStackBasePointer - kSystemPointerSize;
133
134  // Initial size of code buffer.
135  static const int kRegExpCodeSize = 1024;
136
137  void PushCallerSavedRegisters();
138  void PopCallerSavedRegisters();
139
140  // Check whether preemption has been requested.
141  void CheckPreemption();
142
143  // Check whether we are exceeding the stack limit on the backtrack stack.
144  void CheckStackLimit();
145
146  void CallCheckStackGuardState(Register scratch);
147  void CallIsCharacterInRangeArray(const ZoneList<CharacterRange>* ranges);
148
149  // The ebp-relative location of a regexp register.
150  Operand register_location(int register_index);
151
152  // The register containing the current character after LoadCurrentCharacter.
153  static constexpr Register current_character() { return edx; }
154
155  // The register containing the backtrack stack top. Provides a meaningful
156  // name to the register.
157  static constexpr Register backtrack_stackpointer() { return ecx; }
158
159  // Byte size of chars in the string to match (decided by the Mode argument)
160  inline int char_size() const { return static_cast<int>(mode_); }
161
162  // Equivalent to a conditional branch to the label, unless the label
163  // is nullptr, in which case it is a conditional Backtrack.
164  void BranchOrBacktrack(Condition condition, Label* to);
165
166  // Call and return internally in the generated code in a way that
167  // is GC-safe (i.e., doesn't leave absolute code addresses on the stack)
168  inline void SafeCall(Label* to);
169  inline void SafeReturn();
170  inline void SafeCallTarget(Label* name);
171
172  // Pushes the value of a register on the backtrack stack. Decrements the
173  // stack pointer (ecx) by a word size and stores the register's value there.
174  inline void Push(Register source);
175
176  // Pushes a value on the backtrack stack. Decrements the stack pointer (ecx)
177  // by a word size and stores the value there.
178  inline void Push(Immediate value);
179
180  // Pops a value from the backtrack stack. Reads the word at the stack pointer
181  // (ecx) and increments it by a word size.
182  inline void Pop(Register target);
183
184  void LoadRegExpStackPointerFromMemory(Register dst);
185  void StoreRegExpStackPointerToMemory(Register src, Register scratch);
186  void PushRegExpBasePointer(Register stack_pointer, Register scratch);
187  void PopRegExpBasePointer(Register stack_pointer_out, Register scratch);
188
189  Isolate* isolate() const { return masm_->isolate(); }
190
191  const std::unique_ptr<MacroAssembler> masm_;
192  const NoRootArrayScope no_root_array_scope_;
193
194  // Which mode to generate code for (LATIN1 or UC16).
195  const Mode mode_;
196
197  // One greater than maximal register index actually used.
198  int num_registers_;
199
200  // Number of registers to output at the end (the saved registers
201  // are always 0..num_saved_registers_-1).
202  const int num_saved_registers_;
203
204  // Labels used internally.
205  Label entry_label_;
206  Label start_label_;
207  Label success_label_;
208  Label backtrack_label_;
209  Label exit_label_;
210  Label check_preempt_label_;
211  Label stack_overflow_label_;
212  Label fallback_label_;
213};
214
215}  // namespace internal
216}  // namespace v8
217
218#endif  // V8_REGEXP_IA32_REGEXP_MACRO_ASSEMBLER_IA32_H_
219