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 class ArgumentLocation {
47  public:
ArgumentLocation(ManagedRegister reg,size_t size)48   ArgumentLocation(ManagedRegister reg, size_t size)
49       : reg_(reg), frame_offset_(0u), size_(size) {
50     DCHECK(reg.IsRegister());
51   }
52 
ArgumentLocation(FrameOffset frame_offset,size_t size)53   ArgumentLocation(FrameOffset frame_offset, size_t size)
54       : reg_(ManagedRegister::NoRegister()), frame_offset_(frame_offset), size_(size) {}
55 
IsRegister()56   bool IsRegister() const {
57     return reg_.IsRegister();
58   }
59 
GetRegister()60   ManagedRegister GetRegister() const {
61     DCHECK(IsRegister());
62     return reg_;
63   }
64 
GetFrameOffset()65   FrameOffset GetFrameOffset() const {
66     DCHECK(!IsRegister());
67     return frame_offset_;
68   }
69 
GetSize()70   size_t GetSize() const {
71     return size_;
72   }
73 
74  private:
75   ManagedRegister reg_;
76   FrameOffset frame_offset_;
77   size_t size_;
78 };
79 
80 template <PointerSize kPointerSize>
81 class JNIMacroAssembler : public DeletableArenaObject<kArenaAllocAssembler> {
82  public:
83   static std::unique_ptr<JNIMacroAssembler<kPointerSize>> Create(
84       ArenaAllocator* allocator,
85       InstructionSet instruction_set,
86       const InstructionSetFeatures* instruction_set_features = nullptr);
87 
88   // Finalize the code; emit slow paths, fixup branches, add literal pool, etc.
89   virtual void FinalizeCode() = 0;
90 
91   // Size of generated code
92   virtual size_t CodeSize() const = 0;
93 
94   // Copy instructions out of assembly buffer into the given region of memory
95   virtual void FinalizeInstructions(const MemoryRegion& region) = 0;
96 
97   // Emit code that will create an activation on the stack
98   virtual void BuildFrame(size_t frame_size,
99                           ManagedRegister method_reg,
100                           ArrayRef<const ManagedRegister> callee_save_regs) = 0;
101 
102   // Emit code that will remove an activation from the stack
103   //
104   // Argument `may_suspend` must be `true` if the compiled method may be
105   // suspended during its execution (otherwise `false`, if it is impossible
106   // to suspend during its execution).
107   virtual void RemoveFrame(size_t frame_size,
108                            ArrayRef<const ManagedRegister> callee_save_regs,
109                            bool may_suspend) = 0;
110 
111   virtual void IncreaseFrameSize(size_t adjust) = 0;
112   virtual void DecreaseFrameSize(size_t adjust) = 0;
113 
114   // Store routines
115   virtual void Store(FrameOffset offs, ManagedRegister src, size_t size) = 0;
116   virtual void StoreRef(FrameOffset dest, ManagedRegister src) = 0;
117   virtual void StoreRawPtr(FrameOffset dest, ManagedRegister src) = 0;
118 
119   virtual void StoreImmediateToFrame(FrameOffset dest, uint32_t imm) = 0;
120 
121   virtual void StoreStackOffsetToThread(ThreadOffset<kPointerSize> thr_offs,
122                                         FrameOffset fr_offs) = 0;
123 
124   virtual void StoreStackPointerToThread(ThreadOffset<kPointerSize> thr_offs) = 0;
125 
126   virtual void StoreSpanning(FrameOffset dest,
127                              ManagedRegister src,
128                              FrameOffset in_off) = 0;
129 
130   // Load routines
131   virtual void Load(ManagedRegister dest, FrameOffset src, size_t size) = 0;
132 
133   virtual void LoadFromThread(ManagedRegister dest,
134                               ThreadOffset<kPointerSize> src,
135                               size_t size) = 0;
136 
137   virtual void LoadRef(ManagedRegister dest, FrameOffset src) = 0;
138   // If unpoison_reference is true and kPoisonReference is true, then we negate the read reference.
139   virtual void LoadRef(ManagedRegister dest,
140                        ManagedRegister base,
141                        MemberOffset offs,
142                        bool unpoison_reference) = 0;
143 
144   virtual void LoadRawPtr(ManagedRegister dest, ManagedRegister base, Offset offs) = 0;
145 
146   virtual void LoadRawPtrFromThread(ManagedRegister dest, ThreadOffset<kPointerSize> offs) = 0;
147 
148   // Copying routines
149   virtual void MoveArguments(ArrayRef<ArgumentLocation> dests, ArrayRef<ArgumentLocation> srcs) = 0;
150 
151   virtual void Move(ManagedRegister dest, ManagedRegister src, size_t size) = 0;
152 
153   virtual void CopyRawPtrFromThread(FrameOffset fr_offs, ThreadOffset<kPointerSize> thr_offs) = 0;
154 
155   virtual void CopyRawPtrToThread(ThreadOffset<kPointerSize> thr_offs,
156                                   FrameOffset fr_offs,
157                                   ManagedRegister scratch) = 0;
158 
159   virtual void CopyRef(FrameOffset dest, FrameOffset src) = 0;
160   virtual void CopyRef(FrameOffset dest,
161                        ManagedRegister base,
162                        MemberOffset offs,
163                        bool unpoison_reference) = 0;
164 
165   virtual void Copy(FrameOffset dest, FrameOffset src, size_t size) = 0;
166 
167   virtual void Copy(FrameOffset dest,
168                     ManagedRegister src_base,
169                     Offset src_offset,
170                     ManagedRegister scratch,
171                     size_t size) = 0;
172 
173   virtual void Copy(ManagedRegister dest_base,
174                     Offset dest_offset,
175                     FrameOffset src,
176                     ManagedRegister scratch,
177                     size_t size) = 0;
178 
179   virtual void Copy(FrameOffset dest,
180                     FrameOffset src_base,
181                     Offset src_offset,
182                     ManagedRegister scratch,
183                     size_t size) = 0;
184 
185   virtual void Copy(ManagedRegister dest,
186                     Offset dest_offset,
187                     ManagedRegister src,
188                     Offset src_offset,
189                     ManagedRegister scratch,
190                     size_t size) = 0;
191 
192   virtual void Copy(FrameOffset dest,
193                     Offset dest_offset,
194                     FrameOffset src,
195                     Offset src_offset,
196                     ManagedRegister scratch,
197                     size_t size) = 0;
198 
199   virtual void MemoryBarrier(ManagedRegister scratch) = 0;
200 
201   // Sign extension
202   virtual void SignExtend(ManagedRegister mreg, size_t size) = 0;
203 
204   // Zero extension
205   virtual void ZeroExtend(ManagedRegister mreg, size_t size) = 0;
206 
207   // Exploit fast access in managed code to Thread::Current()
208   virtual void GetCurrentThread(ManagedRegister dest) = 0;
209   virtual void GetCurrentThread(FrameOffset dest_offset) = 0;
210 
211   // Set up `out_reg` to hold a `jobject` (`StackReference<Object>*` to a spilled value),
212   // or to be null if the value is null and `null_allowed`. `in_reg` holds a possibly
213   // stale reference that can be used to avoid loading the spilled value to
214   // see if the value is null.
215   virtual void CreateJObject(ManagedRegister out_reg,
216                              FrameOffset spilled_reference_offset,
217                              ManagedRegister in_reg,
218                              bool null_allowed) = 0;
219 
220   // Set up `out_off` to hold a `jobject` (`StackReference<Object>*` to a spilled value),
221   // or to be null if the value is null and `null_allowed`.
222   virtual void CreateJObject(FrameOffset out_off,
223                              FrameOffset spilled_reference_offset,
224                              bool null_allowed) = 0;
225 
226   // Heap::VerifyObject on src. In some cases (such as a reference to this) we
227   // know that src may not be null.
228   virtual void VerifyObject(ManagedRegister src, bool could_be_null) = 0;
229   virtual void VerifyObject(FrameOffset src, bool could_be_null) = 0;
230 
231   // Jump to address held at [base+offset] (used for tail calls).
232   virtual void Jump(ManagedRegister base, Offset offset) = 0;
233 
234   // Call to address held at [base+offset]
235   virtual void Call(ManagedRegister base, Offset offset) = 0;
236   virtual void Call(FrameOffset base, Offset offset) = 0;
237   virtual void CallFromThread(ThreadOffset<kPointerSize> offset) = 0;
238 
239   // Generate code to check if Thread::Current()->exception_ is non-null
240   // and branch to a ExceptionSlowPath if it is.
241   virtual void ExceptionPoll(size_t stack_adjust) = 0;
242 
243   // Create a new label that can be used with Jump/Bind calls.
244   virtual std::unique_ptr<JNIMacroLabel> CreateLabel() = 0;
245   // Emit an unconditional jump to the label.
246   virtual void Jump(JNIMacroLabel* label) = 0;
247   // Emit a conditional jump to the label by applying a unary condition test to the GC marking flag.
248   virtual void TestGcMarking(JNIMacroLabel* label, JNIMacroUnaryCondition cond) = 0;
249   // Code at this offset will serve as the target for the Jump call.
250   virtual void Bind(JNIMacroLabel* label) = 0;
251 
~JNIMacroAssembler()252   virtual ~JNIMacroAssembler() {}
253 
254   /**
255    * @brief Buffer of DWARF's Call Frame Information opcodes.
256    * @details It is used by debuggers and other tools to unwind the call stack.
257    */
258   virtual DebugFrameOpCodeWriterForAssembler& cfi() = 0;
259 
SetEmitRunTimeChecksInDebugMode(bool value)260   void SetEmitRunTimeChecksInDebugMode(bool value) {
261     emit_run_time_checks_in_debug_mode_ = value;
262   }
263 
264  protected:
JNIMacroAssembler()265   JNIMacroAssembler() {}
266 
267   // Should run-time checks be emitted in debug mode?
268   bool emit_run_time_checks_in_debug_mode_ = false;
269 };
270 
271 // A "Label" class used with the JNIMacroAssembler
272 // allowing one to use branches (jumping from one place to another).
273 //
274 // This is just an interface, so every platform must provide
275 // its own implementation of it.
276 //
277 // It is only safe to use a label created
278 // via JNIMacroAssembler::CreateLabel with that same macro assembler.
279 class JNIMacroLabel {
280  public:
281   virtual ~JNIMacroLabel() = 0;
282 
283   const InstructionSet isa_;
284  protected:
JNIMacroLabel(InstructionSet isa)285   explicit JNIMacroLabel(InstructionSet isa) : isa_(isa) {}
286 };
287 
~JNIMacroLabel()288 inline JNIMacroLabel::~JNIMacroLabel() {
289   // Compulsory definition for a pure virtual destructor
290   // to avoid linking errors.
291 }
292 
293 template <typename T, PointerSize kPointerSize>
294 class JNIMacroAssemblerFwd : public JNIMacroAssembler<kPointerSize> {
295  public:
FinalizeCode()296   void FinalizeCode() override {
297     asm_.FinalizeCode();
298   }
299 
CodeSize()300   size_t CodeSize() const override {
301     return asm_.CodeSize();
302   }
303 
FinalizeInstructions(const MemoryRegion & region)304   void FinalizeInstructions(const MemoryRegion& region) override {
305     asm_.FinalizeInstructions(region);
306   }
307 
cfi()308   DebugFrameOpCodeWriterForAssembler& cfi() override {
309     return asm_.cfi();
310   }
311 
312  protected:
JNIMacroAssemblerFwd(ArenaAllocator * allocator)313   explicit JNIMacroAssemblerFwd(ArenaAllocator* allocator) : asm_(allocator) {}
314 
315   T asm_;
316 };
317 
318 template <typename Self, typename PlatformLabel, InstructionSet kIsa>
319 class JNIMacroLabelCommon : public JNIMacroLabel {
320  public:
Cast(JNIMacroLabel * label)321   static Self* Cast(JNIMacroLabel* label) {
322     CHECK(label != nullptr);
323     CHECK_EQ(kIsa, label->isa_);
324 
325     return reinterpret_cast<Self*>(label);
326   }
327 
328  protected:
AsPlatformLabel()329   PlatformLabel* AsPlatformLabel() {
330     return &label_;
331   }
332 
JNIMacroLabelCommon()333   JNIMacroLabelCommon() : JNIMacroLabel(kIsa) {
334   }
335 
~JNIMacroLabelCommon()336   ~JNIMacroLabelCommon() override {}
337 
338  private:
339   PlatformLabel label_;
340 };
341 
342 }  // namespace art
343 
344 #endif  // ART_COMPILER_UTILS_JNI_MACRO_ASSEMBLER_H_
345