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_RUNTIME_ARCH_CONTEXT_H_
18 #define ART_RUNTIME_ARCH_CONTEXT_H_
19 
20 #include <stddef.h>
21 #include <stdint.h>
22 
23 #include "base/macros.h"
24 #include "base/mutex.h"
25 
26 namespace art {
27 
28 class StackVisitor;
29 
30 // Representation of a thread's context on the executing machine, used to implement long jumps in
31 // the quick stack frame layout.
32 class Context {
33  public:
34   // Creates a context for the running architecture
35   static Context* Create();
36 
~Context()37   virtual ~Context() {}
38 
39   // Re-initializes the registers for context re-use.
40   virtual void Reset() = 0;
41 
42   // Reads values from callee saves in the given frame. The frame also holds
43   // the method that holds the layout.
44   virtual void FillCalleeSaves(const StackVisitor& fr)
45       SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) = 0;
46 
47   // Sets the stack pointer value.
48   virtual void SetSP(uintptr_t new_sp) = 0;
49 
50   // Sets the program counter value.
51   virtual void SetPC(uintptr_t new_pc) = 0;
52 
53   // Returns whether the given GPR is accessible (read or write).
54   virtual bool IsAccessibleGPR(uint32_t reg) = 0;
55 
56   // Gets the given GPRs address.
57   virtual uintptr_t* GetGPRAddress(uint32_t reg) = 0;
58 
59   // Reads the given GPR. The caller is responsible for checking the register
60   // is accessible with IsAccessibleGPR.
61   virtual uintptr_t GetGPR(uint32_t reg) = 0;
62 
63   // Sets the given GPR. The caller is responsible for checking the register
64   // is accessible with IsAccessibleGPR.
65   virtual void SetGPR(uint32_t reg, uintptr_t value) = 0;
66 
67   // Returns whether the given FPR is accessible (read or write).
68   virtual bool IsAccessibleFPR(uint32_t reg) = 0;
69 
70   // Reads the given FPR. The caller is responsible for checking the register
71   // is accessible with IsAccessibleFPR.
72   virtual uintptr_t GetFPR(uint32_t reg) = 0;
73 
74   // Sets the given FPR. The caller is responsible for checking the register
75   // is accessible with IsAccessibleFPR.
76   virtual void SetFPR(uint32_t reg, uintptr_t value) = 0;
77 
78   // Smashes the caller save registers. If we're throwing, we don't want to return bogus values.
79   virtual void SmashCallerSaves() = 0;
80 
81   // Switches execution of the executing context to this context
82   NO_RETURN virtual void DoLongJump() = 0;
83 
84  protected:
85   enum {
86     kBadGprBase = 0xebad6070,
87     kBadFprBase = 0xebad8070,
88   };
89 };
90 
91 }  // namespace art
92 
93 #endif  // ART_RUNTIME_ARCH_CONTEXT_H_
94