1 /*
2  * Copyright (C) 2011 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #ifndef ART_COMPILER_UTILS_JNI_MACRO_ASSEMBLER_H_
18 #define ART_COMPILER_UTILS_JNI_MACRO_ASSEMBLER_H_
19 
20 #include <vector>
21 
22 #include <android-base/logging.h>
23 
24 #include "arch/instruction_set.h"
25 #include "base/arena_allocator.h"
26 #include "base/arena_object.h"
27 #include "base/array_ref.h"
28 #include "base/enums.h"
29 #include "base/macros.h"
30 #include "managed_register.h"
31 #include "offsets.h"
32 
33 namespace art {
34 
35 class ArenaAllocator;
36 class DebugFrameOpCodeWriterForAssembler;
37 class InstructionSetFeatures;
38 class MemoryRegion;
39 class JNIMacroLabel;
40 
41 enum class JNIMacroUnaryCondition {
42   kZero,
43   kNotZero
44 };
45 
46 template <PointerSize kPointerSize>
47 class JNIMacroAssembler : public DeletableArenaObject<kArenaAllocAssembler> {
48  public:
49   static std::unique_ptr<JNIMacroAssembler<kPointerSize>> Create(
50       ArenaAllocator* allocator,
51       InstructionSet instruction_set,
52       const InstructionSetFeatures* instruction_set_features = nullptr);
53 
54   // Finalize the code; emit slow paths, fixup branches, add literal pool, etc.
55   virtual void FinalizeCode() = 0;
56 
57   // Size of generated code
58   virtual size_t CodeSize() const = 0;
59 
60   // Copy instructions out of assembly buffer into the given region of memory
61   virtual void FinalizeInstructions(const MemoryRegion& region) = 0;
62 
63   // Emit code that will create an activation on the stack
64   virtual void BuildFrame(size_t frame_size,
65                           ManagedRegister method_reg,
66                           ArrayRef<const ManagedRegister> callee_save_regs,
67                           const ManagedRegisterEntrySpills& entry_spills) = 0;
68 
69   // Emit code that will remove an activation from the stack
70   //
71   // Argument `may_suspend` must be `true` if the compiled method may be
72   // suspended during its execution (otherwise `false`, if it is impossible
73   // to suspend during its execution).
74   virtual void RemoveFrame(size_t frame_size,
75                            ArrayRef<const ManagedRegister> callee_save_regs,
76                            bool may_suspend) = 0;
77 
78   virtual void IncreaseFrameSize(size_t adjust) = 0;
79   virtual void DecreaseFrameSize(size_t adjust) = 0;
80 
81   // Store routines
82   virtual void Store(FrameOffset offs, ManagedRegister src, size_t size) = 0;
83   virtual void StoreRef(FrameOffset dest, ManagedRegister src) = 0;
84   virtual void StoreRawPtr(FrameOffset dest, ManagedRegister src) = 0;
85 
86   virtual void StoreImmediateToFrame(FrameOffset dest, uint32_t imm, ManagedRegister scratch) = 0;
87 
88   virtual void StoreStackOffsetToThread(ThreadOffset<kPointerSize> thr_offs,
89                                         FrameOffset fr_offs,
90                                         ManagedRegister scratch) = 0;
91 
92   virtual void StoreStackPointerToThread(ThreadOffset<kPointerSize> thr_offs) = 0;
93 
94   virtual void StoreSpanning(FrameOffset dest,
95                              ManagedRegister src,
96                              FrameOffset in_off,
97                              ManagedRegister scratch) = 0;
98 
99   // Load routines
100   virtual void Load(ManagedRegister dest, FrameOffset src, size_t size) = 0;
101 
102   virtual void LoadFromThread(ManagedRegister dest,
103                               ThreadOffset<kPointerSize> src,
104                               size_t size) = 0;
105 
106   virtual void LoadRef(ManagedRegister dest, FrameOffset src) = 0;
107   // If unpoison_reference is true and kPoisonReference is true, then we negate the read reference.
108   virtual void LoadRef(ManagedRegister dest,
109                        ManagedRegister base,
110                        MemberOffset offs,
111                        bool unpoison_reference) = 0;
112 
113   virtual void LoadRawPtr(ManagedRegister dest, ManagedRegister base, Offset offs) = 0;
114 
115   virtual void LoadRawPtrFromThread(ManagedRegister dest, ThreadOffset<kPointerSize> offs) = 0;
116 
117   // Copying routines
118   virtual void Move(ManagedRegister dest, ManagedRegister src, size_t size) = 0;
119 
120   virtual void CopyRawPtrFromThread(FrameOffset fr_offs,
121                                     ThreadOffset<kPointerSize> thr_offs,
122                                     ManagedRegister scratch) = 0;
123 
124   virtual void CopyRawPtrToThread(ThreadOffset<kPointerSize> thr_offs,
125                                   FrameOffset fr_offs,
126                                   ManagedRegister scratch) = 0;
127 
128   virtual void CopyRef(FrameOffset dest, FrameOffset src, ManagedRegister scratch) = 0;
129 
130   virtual void Copy(FrameOffset dest, FrameOffset src, ManagedRegister scratch, size_t size) = 0;
131 
132   virtual void Copy(FrameOffset dest,
133                     ManagedRegister src_base,
134                     Offset src_offset,
135                     ManagedRegister scratch,
136                     size_t size) = 0;
137 
138   virtual void Copy(ManagedRegister dest_base,
139                     Offset dest_offset,
140                     FrameOffset src,
141                     ManagedRegister scratch,
142                     size_t size) = 0;
143 
144   virtual void Copy(FrameOffset dest,
145                     FrameOffset src_base,
146                     Offset src_offset,
147                     ManagedRegister scratch,
148                     size_t size) = 0;
149 
150   virtual void Copy(ManagedRegister dest,
151                     Offset dest_offset,
152                     ManagedRegister src,
153                     Offset src_offset,
154                     ManagedRegister scratch,
155                     size_t size) = 0;
156 
157   virtual void Copy(FrameOffset dest,
158                     Offset dest_offset,
159                     FrameOffset src,
160                     Offset src_offset,
161                     ManagedRegister scratch,
162                     size_t size) = 0;
163 
164   virtual void MemoryBarrier(ManagedRegister scratch) = 0;
165 
166   // Sign extension
167   virtual void SignExtend(ManagedRegister mreg, size_t size) = 0;
168 
169   // Zero extension
170   virtual void ZeroExtend(ManagedRegister mreg, size_t size) = 0;
171 
172   // Exploit fast access in managed code to Thread::Current()
173   virtual void GetCurrentThread(ManagedRegister tr) = 0;
174   virtual void GetCurrentThread(FrameOffset dest_offset, ManagedRegister scratch) = 0;
175 
176   // Set up out_reg to hold a Object** into the handle scope, or to be null if the
177   // value is null and null_allowed. in_reg holds a possibly stale reference
178   // that can be used to avoid loading the handle scope entry to see if the value is
179   // null.
180   virtual void CreateHandleScopeEntry(ManagedRegister out_reg,
181                                       FrameOffset handlescope_offset,
182                                       ManagedRegister in_reg,
183                                       bool null_allowed) = 0;
184 
185   // Set up out_off to hold a Object** into the handle scope, or to be null if the
186   // value is null and null_allowed.
187   virtual void CreateHandleScopeEntry(FrameOffset out_off,
188                                       FrameOffset handlescope_offset,
189                                       ManagedRegister scratch,
190                                       bool null_allowed) = 0;
191 
192   // src holds a handle scope entry (Object**) load this into dst
193   virtual void LoadReferenceFromHandleScope(ManagedRegister dst, ManagedRegister src) = 0;
194 
195   // Heap::VerifyObject on src. In some cases (such as a reference to this) we
196   // know that src may not be null.
197   virtual void VerifyObject(ManagedRegister src, bool could_be_null) = 0;
198   virtual void VerifyObject(FrameOffset src, bool could_be_null) = 0;
199 
200   // Jump to address held at [base+offset] (used for tail calls).
201   virtual void Jump(ManagedRegister base, Offset offset, ManagedRegister scratch) = 0;
202 
203   // Call to address held at [base+offset]
204   virtual void Call(ManagedRegister base, Offset offset, ManagedRegister scratch) = 0;
205   virtual void Call(FrameOffset base, Offset offset, ManagedRegister scratch) = 0;
206   virtual void CallFromThread(ThreadOffset<kPointerSize> offset, ManagedRegister scratch) = 0;
207 
208   // Generate code to check if Thread::Current()->exception_ is non-null
209   // and branch to a ExceptionSlowPath if it is.
210   virtual void ExceptionPoll(ManagedRegister scratch, size_t stack_adjust) = 0;
211 
212   // Create a new label that can be used with Jump/Bind calls.
213   virtual std::unique_ptr<JNIMacroLabel> CreateLabel() = 0;
214   // Emit an unconditional jump to the label.
215   virtual void Jump(JNIMacroLabel* label) = 0;
216   // Emit a conditional jump to the label by applying a unary condition test to the register.
217   virtual void Jump(JNIMacroLabel* label, JNIMacroUnaryCondition cond, ManagedRegister test) = 0;
218   // Code at this offset will serve as the target for the Jump call.
219   virtual void Bind(JNIMacroLabel* label) = 0;
220 
~JNIMacroAssembler()221   virtual ~JNIMacroAssembler() {}
222 
223   /**
224    * @brief Buffer of DWARF's Call Frame Information opcodes.
225    * @details It is used by debuggers and other tools to unwind the call stack.
226    */
227   virtual DebugFrameOpCodeWriterForAssembler& cfi() = 0;
228 
SetEmitRunTimeChecksInDebugMode(bool value)229   void SetEmitRunTimeChecksInDebugMode(bool value) {
230     emit_run_time_checks_in_debug_mode_ = value;
231   }
232 
233  protected:
JNIMacroAssembler()234   JNIMacroAssembler() {}
235 
236   // Should run-time checks be emitted in debug mode?
237   bool emit_run_time_checks_in_debug_mode_ = false;
238 };
239 
240 // A "Label" class used with the JNIMacroAssembler
241 // allowing one to use branches (jumping from one place to another).
242 //
243 // This is just an interface, so every platform must provide
244 // its own implementation of it.
245 //
246 // It is only safe to use a label created
247 // via JNIMacroAssembler::CreateLabel with that same macro assembler.
248 class JNIMacroLabel {
249  public:
250   virtual ~JNIMacroLabel() = 0;
251 
252   const InstructionSet isa_;
253  protected:
JNIMacroLabel(InstructionSet isa)254   explicit JNIMacroLabel(InstructionSet isa) : isa_(isa) {}
255 };
256 
~JNIMacroLabel()257 inline JNIMacroLabel::~JNIMacroLabel() {
258   // Compulsory definition for a pure virtual destructor
259   // to avoid linking errors.
260 }
261 
262 template <typename T, PointerSize kPointerSize>
263 class JNIMacroAssemblerFwd : public JNIMacroAssembler<kPointerSize> {
264  public:
FinalizeCode()265   void FinalizeCode() override {
266     asm_.FinalizeCode();
267   }
268 
CodeSize()269   size_t CodeSize() const override {
270     return asm_.CodeSize();
271   }
272 
FinalizeInstructions(const MemoryRegion & region)273   void FinalizeInstructions(const MemoryRegion& region) override {
274     asm_.FinalizeInstructions(region);
275   }
276 
cfi()277   DebugFrameOpCodeWriterForAssembler& cfi() override {
278     return asm_.cfi();
279   }
280 
281  protected:
JNIMacroAssemblerFwd(ArenaAllocator * allocator)282   explicit JNIMacroAssemblerFwd(ArenaAllocator* allocator) : asm_(allocator) {}
283 
284   T asm_;
285 };
286 
287 template <typename Self, typename PlatformLabel, InstructionSet kIsa>
288 class JNIMacroLabelCommon : public JNIMacroLabel {
289  public:
Cast(JNIMacroLabel * label)290   static Self* Cast(JNIMacroLabel* label) {
291     CHECK(label != nullptr);
292     CHECK_EQ(kIsa, label->isa_);
293 
294     return reinterpret_cast<Self*>(label);
295   }
296 
297  protected:
AsPlatformLabel()298   PlatformLabel* AsPlatformLabel() {
299     return &label_;
300   }
301 
JNIMacroLabelCommon()302   JNIMacroLabelCommon() : JNIMacroLabel(kIsa) {
303   }
304 
~JNIMacroLabelCommon()305   ~JNIMacroLabelCommon() override {}
306 
307  private:
308   PlatformLabel label_;
309 };
310 
311 }  // namespace art
312 
313 #endif  // ART_COMPILER_UTILS_JNI_MACRO_ASSEMBLER_H_
314