1 //===- RemoteMemoryManager.h - LLI MCJIT recording memory manager ------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This memory manager allocates local storage and keeps a record of each
11 // allocation. Iterators are provided for all data and code allocations.
12 //
13 //===----------------------------------------------------------------------===//
14 
15 #ifndef LLVM_TOOLS_LLI_REMOTEMEMORYMANAGER_H
16 #define LLVM_TOOLS_LLI_REMOTEMEMORYMANAGER_H
17 
18 #include "RemoteTarget.h"
19 #include "llvm/ADT/DenseMap.h"
20 #include "llvm/ADT/SmallVector.h"
21 #include "llvm/ExecutionEngine/RTDyldMemoryManager.h"
22 #include "llvm/Support/ErrorHandling.h"
23 #include "llvm/Support/Memory.h"
24 #include <utility>
25 
26 namespace llvm {
27 
28 class RemoteMemoryManager : public RTDyldMemoryManager {
29 public:
30   // Notice that this structure takes ownership of the memory allocated.
31   struct Allocation {
AllocationAllocation32     Allocation() {}
AllocationAllocation33     Allocation(sys::MemoryBlock mb, unsigned a, bool code)
34       : MB(mb), Alignment(a), IsCode(code) {}
35 
36     sys::MemoryBlock  MB;
37     unsigned          Alignment;
38     bool              IsCode;
39   };
40 
41 private:
42   // This vector contains Allocation objects for all sections which we have
43   // allocated.  This vector effectively owns the memory associated with the
44   // allocations.
45   SmallVector<Allocation, 2>  AllocatedSections;
46 
47   // This vector contains pointers to Allocation objects for any sections we
48   // have allocated locally but have not yet remapped for the remote target.
49   // When we receive notification of a completed module load, we will map
50   // these sections into the remote target.
51   SmallVector<Allocation, 2>  UnmappedSections;
52 
53   // This map tracks the sections we have remapped for the remote target
54   // but have not yet copied to the target.
55   DenseMap<uint64_t, Allocation>  MappedSections;
56 
57   // FIXME: This is part of a work around to keep sections near one another
58   // when MCJIT performs relocations after code emission but before
59   // the generated code is moved to the remote target.
60   sys::MemoryBlock Near;
61   sys::MemoryBlock allocateSection(uintptr_t Size);
62 
63   RemoteTarget *Target;
64 
65 public:
RemoteMemoryManager()66   RemoteMemoryManager() : Target(nullptr) {}
67   ~RemoteMemoryManager() override;
68 
69   uint8_t *allocateCodeSection(uintptr_t Size, unsigned Alignment,
70                                unsigned SectionID,
71                                StringRef SectionName) override;
72 
73   uint8_t *allocateDataSection(uintptr_t Size, unsigned Alignment,
74                                unsigned SectionID, StringRef SectionName,
75                                bool IsReadOnly) override;
76 
77   // For now, remote symbol resolution is not support in lli.  The MCJIT
78   // interface does support this, but clients must provide their own
79   // mechanism for finding remote symbol addresses.  MCJIT will resolve
80   // symbols from Modules it contains.
getSymbolAddress(const std::string & Name)81   uint64_t getSymbolAddress(const std::string &Name) override { return 0; }
82 
83   void notifyObjectLoaded(ExecutionEngine *EE,
84                           const object::ObjectFile &Obj) override;
85 
86   bool finalizeMemory(std::string *ErrMsg) override;
87 
88   // For now, remote EH frame registration isn't supported.  Remote symbol
89   // resolution is a prerequisite to supporting remote EH frame registration.
registerEHFrames(uint8_t * Addr,uint64_t LoadAddr,size_t Size)90   void registerEHFrames(uint8_t *Addr, uint64_t LoadAddr,
91                         size_t Size) override {}
deregisterEHFrames(uint8_t * Addr,uint64_t LoadAddr,size_t Size)92   void deregisterEHFrames(uint8_t *Addr, uint64_t LoadAddr,
93                           size_t Size) override {}
94 
95   // This is a non-interface function used by lli
setRemoteTarget(RemoteTarget * T)96   void setRemoteTarget(RemoteTarget *T) { Target = T; }
97 };
98 
99 } // end namespace llvm
100 
101 #endif
102