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1 // Copyright 2006-2008 the V8 project authors. All rights reserved.
2 // Redistribution and use in source and binary forms, with or without
3 // modification, are permitted provided that the following conditions are
4 // met:
5 //
6 //     * Redistributions of source code must retain the above copyright
7 //       notice, this list of conditions and the following disclaimer.
8 //     * Redistributions in binary form must reproduce the above
9 //       copyright notice, this list of conditions and the following
10 //       disclaimer in the documentation and/or other materials provided
11 //       with the distribution.
12 //     * Neither the name of Google Inc. nor the names of its
13 //       contributors may be used to endorse or promote products derived
14 //       from this software without specific prior written permission.
15 //
16 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
17 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
18 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
19 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
20 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
21 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
22 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
26 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 
28 #ifndef V8_ARM_REGEXP_MACRO_ASSEMBLER_ARM_H_
29 #define V8_ARM_REGEXP_MACRO_ASSEMBLER_ARM_H_
30 
31 namespace v8 {
32 namespace internal {
33 
34 
35 #ifdef V8_INTERPRETED_REGEXP
36 class RegExpMacroAssemblerARM: public RegExpMacroAssembler {
37  public:
38   RegExpMacroAssemblerARM();
39   virtual ~RegExpMacroAssemblerARM();
40 };
41 
42 #else  // V8_INTERPRETED_REGEXP
43 class RegExpMacroAssemblerARM: public NativeRegExpMacroAssembler {
44  public:
45   RegExpMacroAssemblerARM(Mode mode, int registers_to_save);
46   virtual ~RegExpMacroAssemblerARM();
47   virtual int stack_limit_slack();
48   virtual void AdvanceCurrentPosition(int by);
49   virtual void AdvanceRegister(int reg, int by);
50   virtual void Backtrack();
51   virtual void Bind(Label* label);
52   virtual void CheckAtStart(Label* on_at_start);
53   virtual void CheckCharacter(unsigned c, Label* on_equal);
54   virtual void CheckCharacterAfterAnd(unsigned c,
55                                       unsigned mask,
56                                       Label* on_equal);
57   virtual void CheckCharacterGT(uc16 limit, Label* on_greater);
58   virtual void CheckCharacterLT(uc16 limit, Label* on_less);
59   virtual void CheckCharacters(Vector<const uc16> str,
60                                int cp_offset,
61                                Label* on_failure,
62                                bool check_end_of_string);
63   // A "greedy loop" is a loop that is both greedy and with a simple
64   // body. It has a particularly simple implementation.
65   virtual void CheckGreedyLoop(Label* on_tos_equals_current_position);
66   virtual void CheckNotAtStart(Label* on_not_at_start);
67   virtual void CheckNotBackReference(int start_reg, Label* on_no_match);
68   virtual void CheckNotBackReferenceIgnoreCase(int start_reg,
69                                                Label* on_no_match);
70   virtual void CheckNotRegistersEqual(int reg1, int reg2, Label* on_not_equal);
71   virtual void CheckNotCharacter(unsigned c, Label* on_not_equal);
72   virtual void CheckNotCharacterAfterAnd(unsigned c,
73                                          unsigned mask,
74                                          Label* on_not_equal);
75   virtual void CheckNotCharacterAfterMinusAnd(uc16 c,
76                                               uc16 minus,
77                                               uc16 mask,
78                                               Label* on_not_equal);
79   // Checks whether the given offset from the current position is before
80   // the end of the string.
81   virtual void CheckPosition(int cp_offset, Label* on_outside_input);
82   virtual bool CheckSpecialCharacterClass(uc16 type,
83                                           Label* on_no_match);
84   virtual void Fail();
85   virtual Handle<HeapObject> GetCode(Handle<String> source);
86   virtual void GoTo(Label* label);
87   virtual void IfRegisterGE(int reg, int comparand, Label* if_ge);
88   virtual void IfRegisterLT(int reg, int comparand, Label* if_lt);
89   virtual void IfRegisterEqPos(int reg, Label* if_eq);
90   virtual IrregexpImplementation Implementation();
91   virtual void LoadCurrentCharacter(int cp_offset,
92                                     Label* on_end_of_input,
93                                     bool check_bounds = true,
94                                     int characters = 1);
95   virtual void PopCurrentPosition();
96   virtual void PopRegister(int register_index);
97   virtual void PushBacktrack(Label* label);
98   virtual void PushCurrentPosition();
99   virtual void PushRegister(int register_index,
100                             StackCheckFlag check_stack_limit);
101   virtual void ReadCurrentPositionFromRegister(int reg);
102   virtual void ReadStackPointerFromRegister(int reg);
103   virtual void SetCurrentPositionFromEnd(int by);
104   virtual void SetRegister(int register_index, int to);
105   virtual void Succeed();
106   virtual void WriteCurrentPositionToRegister(int reg, int cp_offset);
107   virtual void ClearRegisters(int reg_from, int reg_to);
108   virtual void WriteStackPointerToRegister(int reg);
109 
110   // Called from RegExp if the stack-guard is triggered.
111   // If the code object is relocated, the return address is fixed before
112   // returning.
113   static int CheckStackGuardState(Address* return_address,
114                                   Code* re_code,
115                                   Address re_frame);
116  private:
117   // Offsets from frame_pointer() of function parameters and stored registers.
118   static const int kFramePointer = 0;
119 
120   // Above the frame pointer - Stored registers and stack passed parameters.
121   // Register 4..11.
122   static const int kStoredRegisters = kFramePointer;
123   // Return address (stored from link register, read into pc on return).
124   static const int kReturnAddress = kStoredRegisters + 8 * kPointerSize;
125   static const int kSecondaryReturnAddress = kReturnAddress + kPointerSize;
126   // Stack parameters placed by caller.
127   static const int kRegisterOutput = kSecondaryReturnAddress + kPointerSize;
128   static const int kStackHighEnd = kRegisterOutput + kPointerSize;
129   static const int kDirectCall = kStackHighEnd + kPointerSize;
130   static const int kIsolate = kDirectCall + kPointerSize;
131 
132   // Below the frame pointer.
133   // Register parameters stored by setup code.
134   static const int kInputEnd = kFramePointer - kPointerSize;
135   static const int kInputStart = kInputEnd - kPointerSize;
136   static const int kStartIndex = kInputStart - kPointerSize;
137   static const int kInputString = kStartIndex - kPointerSize;
138   // When adding local variables remember to push space for them in
139   // the frame in GetCode.
140   static const int kInputStartMinusOne = kInputString - kPointerSize;
141   static const int kAtStart = kInputStartMinusOne - kPointerSize;
142   // First register address. Following registers are below it on the stack.
143   static const int kRegisterZero = kAtStart - kPointerSize;
144 
145   // Initial size of code buffer.
146   static const size_t kRegExpCodeSize = 1024;
147 
148   static const int kBacktrackConstantPoolSize = 4;
149 
150   // Load a number of characters at the given offset from the
151   // current position, into the current-character register.
152   void LoadCurrentCharacterUnchecked(int cp_offset, int character_count);
153 
154   // Check whether preemption has been requested.
155   void CheckPreemption();
156 
157   // Check whether we are exceeding the stack limit on the backtrack stack.
158   void CheckStackLimit();
159 
160   void EmitBacktrackConstantPool();
161   int GetBacktrackConstantPoolEntry();
162 
163 
164   // Generate a call to CheckStackGuardState.
165   void CallCheckStackGuardState(Register scratch);
166 
167   // The ebp-relative location of a regexp register.
168   MemOperand register_location(int register_index);
169 
170   // Register holding the current input position as negative offset from
171   // the end of the string.
172   inline Register current_input_offset() { return r6; }
173 
174   // The register containing the current character after LoadCurrentCharacter.
175   inline Register current_character() { return r7; }
176 
177   // Register holding address of the end of the input string.
178   inline Register end_of_input_address() { return r10; }
179 
180   // Register holding the frame address. Local variables, parameters and
181   // regexp registers are addressed relative to this.
182   inline Register frame_pointer() { return fp; }
183 
184   // The register containing the backtrack stack top. Provides a meaningful
185   // name to the register.
186   inline Register backtrack_stackpointer() { return r8; }
187 
188   // Register holding pointer to the current code object.
189   inline Register code_pointer() { return r5; }
190 
191   // Byte size of chars in the string to match (decided by the Mode argument)
192   inline int char_size() { return static_cast<int>(mode_); }
193 
194   // Equivalent to a conditional branch to the label, unless the label
195   // is NULL, in which case it is a conditional Backtrack.
196   void BranchOrBacktrack(Condition condition, Label* to);
197 
198   // Call and return internally in the generated code in a way that
199   // is GC-safe (i.e., doesn't leave absolute code addresses on the stack)
200   inline void SafeCall(Label* to, Condition cond = al);
201   inline void SafeReturn();
202   inline void SafeCallTarget(Label* name);
203 
204   // Pushes the value of a register on the backtrack stack. Decrements the
205   // stack pointer by a word size and stores the register's value there.
206   inline void Push(Register source);
207 
208   // Pops a value from the backtrack stack. Reads the word at the stack pointer
209   // and increments it by a word size.
210   inline void Pop(Register target);
211 
212   // Calls a C function and cleans up the frame alignment done by
213   // by FrameAlign. The called function *is* allowed to trigger a garbage
214   // collection, but may not take more than four arguments (no arguments
215   // passed on the stack), and the first argument will be a pointer to the
216   // return address.
217   inline void CallCFunctionUsingStub(ExternalReference function,
218                                      int num_arguments);
219 
220 
221   MacroAssembler* masm_;
222 
223   // Which mode to generate code for (ASCII or UC16).
224   Mode mode_;
225 
226   // One greater than maximal register index actually used.
227   int num_registers_;
228 
229   // Number of registers to output at the end (the saved registers
230   // are always 0..num_saved_registers_-1)
231   int num_saved_registers_;
232 
233   // Manage a small pre-allocated pool for writing label targets
234   // to for pushing backtrack addresses.
235   int backtrack_constant_pool_offset_;
236   int backtrack_constant_pool_capacity_;
237 
238   // Labels used internally.
239   Label entry_label_;
240   Label start_label_;
241   Label success_label_;
242   Label backtrack_label_;
243   Label exit_label_;
244   Label check_preempt_label_;
245   Label stack_overflow_label_;
246 };
247 
248 #endif  // V8_INTERPRETED_REGEXP
249 
250 
251 }}  // namespace v8::internal
252 
253 #endif  // V8_ARM_REGEXP_MACRO_ASSEMBLER_ARM_H_
254