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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/macro-assembler.h"
9 #include "src/regexp/regexp-macro-assembler.h"
10 
11 namespace v8 {
12 namespace internal {
13 
14 class 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.
current_input_offset()146   static constexpr Register current_input_offset() { return r6; }
147 
148   // The register containing the current character after LoadCurrentCharacter.
current_character()149   static constexpr Register current_character() { return r7; }
150 
151   // Register holding address of the end of the input string.
end_of_input_address()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.
frame_pointer()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.
backtrack_stackpointer()160   static constexpr Register backtrack_stackpointer() { return r8; }
161 
162   // Register holding pointer to the current code object.
code_pointer()163   static constexpr Register code_pointer() { return r5; }
164 
165   // Byte size of chars in the string to match (decided by the Mode argument)
char_size()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 
isolate()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