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