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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/arm/assembler-arm.h"
9 #include "src/macro-assembler.h"
10 #include "src/regexp/regexp-macro-assembler.h"
11 
12 namespace v8 {
13 namespace internal {
14 
15 
16 #ifndef V8_INTERPRETED_REGEXP
17 class RegExpMacroAssemblerARM: public NativeRegExpMacroAssembler {
18  public:
19   RegExpMacroAssemblerARM(Isolate* isolate, Zone* zone, Mode mode,
20                           int registers_to_save);
21   virtual ~RegExpMacroAssemblerARM();
22   virtual int stack_limit_slack();
23   virtual void AdvanceCurrentPosition(int by);
24   virtual void AdvanceRegister(int reg, int by);
25   virtual void Backtrack();
26   virtual void Bind(Label* label);
27   virtual void CheckAtStart(Label* on_at_start);
28   virtual void CheckCharacter(unsigned c, Label* on_equal);
29   virtual void CheckCharacterAfterAnd(unsigned c,
30                                       unsigned mask,
31                                       Label* on_equal);
32   virtual void CheckCharacterGT(uc16 limit, Label* on_greater);
33   virtual void CheckCharacterLT(uc16 limit, Label* on_less);
34   // A "greedy loop" is a loop that is both greedy and with a simple
35   // body. It has a particularly simple implementation.
36   virtual void CheckGreedyLoop(Label* on_tos_equals_current_position);
37   virtual void CheckNotAtStart(int cp_offset, Label* on_not_at_start);
38   virtual void CheckNotBackReference(int start_reg, bool read_backward,
39                                      Label* on_no_match);
40   virtual void CheckNotBackReferenceIgnoreCase(int start_reg,
41                                                bool read_backward, bool unicode,
42                                                Label* on_no_match);
43   virtual void CheckNotCharacter(unsigned c, Label* on_not_equal);
44   virtual void CheckNotCharacterAfterAnd(unsigned c,
45                                          unsigned mask,
46                                          Label* on_not_equal);
47   virtual void CheckNotCharacterAfterMinusAnd(uc16 c,
48                                               uc16 minus,
49                                               uc16 mask,
50                                               Label* on_not_equal);
51   virtual void CheckCharacterInRange(uc16 from,
52                                      uc16 to,
53                                      Label* on_in_range);
54   virtual void CheckCharacterNotInRange(uc16 from,
55                                         uc16 to,
56                                         Label* on_not_in_range);
57   virtual void CheckBitInTable(Handle<ByteArray> table, Label* on_bit_set);
58 
59   // Checks whether the given offset from the current position is before
60   // the end of the string.
61   virtual void CheckPosition(int cp_offset, Label* on_outside_input);
62   virtual bool CheckSpecialCharacterClass(uc16 type,
63                                           Label* on_no_match);
64   virtual void Fail();
65   virtual Handle<HeapObject> GetCode(Handle<String> source);
66   virtual void GoTo(Label* label);
67   virtual void IfRegisterGE(int reg, int comparand, Label* if_ge);
68   virtual void IfRegisterLT(int reg, int comparand, Label* if_lt);
69   virtual void IfRegisterEqPos(int reg, Label* if_eq);
70   virtual IrregexpImplementation Implementation();
71   virtual void LoadCurrentCharacter(int cp_offset,
72                                     Label* on_end_of_input,
73                                     bool check_bounds = true,
74                                     int characters = 1);
75   virtual void PopCurrentPosition();
76   virtual void PopRegister(int register_index);
77   virtual void PushBacktrack(Label* label);
78   virtual void PushCurrentPosition();
79   virtual void PushRegister(int register_index,
80                             StackCheckFlag check_stack_limit);
81   virtual void ReadCurrentPositionFromRegister(int reg);
82   virtual void ReadStackPointerFromRegister(int reg);
83   virtual void SetCurrentPositionFromEnd(int by);
84   virtual void SetRegister(int register_index, int to);
85   virtual bool Succeed();
86   virtual void WriteCurrentPositionToRegister(int reg, int cp_offset);
87   virtual void ClearRegisters(int reg_from, int reg_to);
88   virtual void WriteStackPointerToRegister(int reg);
89 
90   // Called from RegExp if the stack-guard is triggered.
91   // If the code object is relocated, the return address is fixed before
92   // returning.
93   static int CheckStackGuardState(Address* return_address,
94                                   Code* re_code,
95                                   Address re_frame);
96 
97  private:
98   // Offsets from frame_pointer() of function parameters and stored registers.
99   static const int kFramePointer = 0;
100 
101   // Above the frame pointer - Stored registers and stack passed parameters.
102   // Register 4..11.
103   static const int kStoredRegisters = kFramePointer;
104   // Return address (stored from link register, read into pc on return).
105   static const int kReturnAddress = kStoredRegisters + 8 * kPointerSize;
106   // Stack parameters placed by caller.
107   static const int kRegisterOutput = kReturnAddress + kPointerSize;
108   static const int kNumOutputRegisters = kRegisterOutput + kPointerSize;
109   static const int kStackHighEnd = kNumOutputRegisters + kPointerSize;
110   static const int kDirectCall = kStackHighEnd + kPointerSize;
111   static const int kIsolate = kDirectCall + kPointerSize;
112 
113   // Below the frame pointer.
114   // Register parameters stored by setup code.
115   static const int kInputEnd = kFramePointer - kPointerSize;
116   static const int kInputStart = kInputEnd - kPointerSize;
117   static const int kStartIndex = kInputStart - kPointerSize;
118   static const int kInputString = kStartIndex - kPointerSize;
119   // When adding local variables remember to push space for them in
120   // the frame in GetCode.
121   static const int kSuccessfulCaptures = kInputString - kPointerSize;
122   static const int kStringStartMinusOne = kSuccessfulCaptures - kPointerSize;
123   // First register address. Following registers are below it on the stack.
124   static const int kRegisterZero = kStringStartMinusOne - kPointerSize;
125 
126   // Initial size of code buffer.
127   static const size_t kRegExpCodeSize = 1024;
128 
129   static const int kBacktrackConstantPoolSize = 4;
130 
131   // Load a number of characters at the given offset from the
132   // current position, into the current-character register.
133   void LoadCurrentCharacterUnchecked(int cp_offset, int character_count);
134 
135   // Check whether preemption has been requested.
136   void CheckPreemption();
137 
138   // Check whether we are exceeding the stack limit on the backtrack stack.
139   void CheckStackLimit();
140 
141 
142   // Generate a call to CheckStackGuardState.
143   void CallCheckStackGuardState();
144 
145   // The ebp-relative location of a regexp register.
146   MemOperand register_location(int register_index);
147 
148   // Register holding the current input position as negative offset from
149   // the end of the string.
current_input_offset()150   inline Register current_input_offset() { return r6; }
151 
152   // The register containing the current character after LoadCurrentCharacter.
current_character()153   inline Register current_character() { return r7; }
154 
155   // Register holding address of the end of the input string.
end_of_input_address()156   inline Register end_of_input_address() { return r10; }
157 
158   // Register holding the frame address. Local variables, parameters and
159   // regexp registers are addressed relative to this.
frame_pointer()160   inline Register frame_pointer() { return fp; }
161 
162   // The register containing the backtrack stack top. Provides a meaningful
163   // name to the register.
backtrack_stackpointer()164   inline Register backtrack_stackpointer() { return r8; }
165 
166   // Register holding pointer to the current code object.
code_pointer()167   inline Register code_pointer() { return r5; }
168 
169   // Byte size of chars in the string to match (decided by the Mode argument)
char_size()170   inline int char_size() { return static_cast<int>(mode_); }
171 
172   // Equivalent to a conditional branch to the label, unless the label
173   // is nullptr, in which case it is a conditional Backtrack.
174   void BranchOrBacktrack(Condition condition, Label* to);
175 
176   // Call and return internally in the generated code in a way that
177   // is GC-safe (i.e., doesn't leave absolute code addresses on the stack)
178   inline void SafeCall(Label* to, Condition cond = al);
179   inline void SafeReturn();
180   inline void SafeCallTarget(Label* name);
181 
182   // Pushes the value of a register on the backtrack stack. Decrements the
183   // stack pointer by a word size and stores the register's value there.
184   inline void Push(Register source);
185 
186   // Pops a value from the backtrack stack. Reads the word at the stack pointer
187   // and increments it by a word size.
188   inline void Pop(Register target);
189 
isolate()190   Isolate* isolate() const { return masm_->isolate(); }
191 
192   MacroAssembler* masm_;
193 
194   // Which mode to generate code for (Latin1 or UC16).
195   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   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 };
213 
214 #endif  // V8_INTERPRETED_REGEXP
215 
216 
217 }  // namespace internal
218 }  // namespace v8
219 
220 #endif  // V8_REGEXP_ARM_REGEXP_MACRO_ASSEMBLER_ARM_H_
221