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
26namespace llvm {
27
28class RemoteMemoryManager : public RTDyldMemoryManager {
29public:
30  // Notice that this structure takes ownership of the memory allocated.
31  struct Allocation {
32    Allocation() {}
33    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
41private:
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
65public:
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.
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.
90  void registerEHFrames(uint8_t *Addr, uint64_t LoadAddr,
91                        size_t Size) override {}
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
96  void setRemoteTarget(RemoteTarget *T) { Target = T; }
97};
98
99} // end namespace llvm
100
101#endif
102