1 //===-- RTDyldMemoryManager.cpp - Memory manager for MC-JIT -----*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // Interface of the runtime dynamic memory manager base class.
12 //===----------------------------------------------------------------------===//
14 #ifndef LLVM_EXECUTIONENGINE_RTDYLDMEMORYMANAGER_H
15 #define LLVM_EXECUTIONENGINE_RTDYLDMEMORYMANAGER_H
17 #include "llvm-c/ExecutionEngine.h"
18 #include "llvm/ADT/StringRef.h"
19 #include "llvm/Support/CBindingWrapping.h"
20 #include "llvm/Support/Memory.h"
24 class ExecutionEngine;
30 // RuntimeDyld clients often want to handle the memory management of
31 // what gets placed where. For JIT clients, this is the subset of
32 // JITMemoryManager required for dynamic loading of binaries.
34 // FIXME: As the RuntimeDyld fills out, additional routines will be needed
35 // for the varying types of objects to be allocated.
36 class RTDyldMemoryManager {
37 RTDyldMemoryManager(const RTDyldMemoryManager&) = delete;
38 void operator=(const RTDyldMemoryManager&) = delete;
40 RTDyldMemoryManager() {}
41 virtual ~RTDyldMemoryManager();
43 /// Allocate a memory block of (at least) the given size suitable for
44 /// executable code. The SectionID is a unique identifier assigned by the JIT
45 /// engine, and optionally recorded by the memory manager to access a loaded
47 virtual uint8_t *allocateCodeSection(
48 uintptr_t Size, unsigned Alignment, unsigned SectionID,
49 StringRef SectionName) = 0;
51 /// Allocate a memory block of (at least) the given size suitable for data.
52 /// The SectionID is a unique identifier assigned by the JIT engine, and
53 /// optionally recorded by the memory manager to access a loaded section.
54 virtual uint8_t *allocateDataSection(
55 uintptr_t Size, unsigned Alignment, unsigned SectionID,
56 StringRef SectionName, bool IsReadOnly) = 0;
58 /// Inform the memory manager about the total amount of memory required to
59 /// allocate all sections to be loaded:
60 /// \p CodeSize - the total size of all code sections
61 /// \p DataSizeRO - the total size of all read-only data sections
62 /// \p DataSizeRW - the total size of all read-write data sections
64 /// Note that by default the callback is disabled. To enable it
65 /// redefine the method needsToReserveAllocationSpace to return true.
66 virtual void reserveAllocationSpace(
67 uintptr_t CodeSize, uintptr_t DataSizeRO, uintptr_t DataSizeRW) { }
69 /// Override to return true to enable the reserveAllocationSpace callback.
70 virtual bool needsToReserveAllocationSpace() { return false; }
72 /// Register the EH frames with the runtime so that c++ exceptions work.
74 /// \p Addr parameter provides the local address of the EH frame section
75 /// data, while \p LoadAddr provides the address of the data in the target
76 /// address space. If the section has not been remapped (which will usually
77 /// be the case for local execution) these two values will be the same.
78 virtual void registerEHFrames(uint8_t *Addr, uint64_t LoadAddr, size_t Size);
80 virtual void deregisterEHFrames(uint8_t *Addr, uint64_t LoadAddr, size_t Size);
82 /// This method returns the address of the specified function or variable in
83 /// the current process.
84 static uint64_t getSymbolAddressInProcess(const std::string &Name);
86 /// This method returns the address of the specified function or variable.
87 /// It is used to resolve symbols during module linking.
88 virtual uint64_t getSymbolAddress(const std::string &Name) {
89 return getSymbolAddressInProcess(Name);
92 /// This method returns the address of the specified symbol if it exists
93 /// within the logical dynamic library represented by this
94 /// RTDyldMemoryManager. Unlike getSymbolAddress, queries through this
95 /// interface should return addresses for hidden symbols.
97 /// This is of particular importance for the Orc JIT APIs, which support lazy
98 /// compilation by breaking up modules: Each of those broken out modules
99 /// must be able to resolve hidden symbols provided by the others. Clients
100 /// writing memory managers for MCJIT can usually ignore this method.
102 /// This method will be queried by RuntimeDyld when checking for previous
103 /// definitions of common symbols. It will *not* be queried by default when
104 /// resolving external symbols (this minimises the link-time overhead for
105 /// MCJIT clients who don't care about Orc features). If you are writing a
106 /// RTDyldMemoryManager for Orc and want "external" symbol resolution to
107 /// search the logical dylib, you should override your getSymbolAddress
108 /// method call this method directly.
109 virtual uint64_t getSymbolAddressInLogicalDylib(const std::string &Name) {
113 /// This method returns the address of the specified function. As such it is
114 /// only useful for resolving library symbols, not code generated symbols.
116 /// If \p AbortOnFailure is false and no function with the given name is
117 /// found, this function returns a null pointer. Otherwise, it prints a
118 /// message to stderr and aborts.
120 /// This function is deprecated for memory managers to be used with
121 /// MCJIT or RuntimeDyld. Use getSymbolAddress instead.
122 virtual void *getPointerToNamedFunction(const std::string &Name,
123 bool AbortOnFailure = true);
125 /// This method is called after an object has been loaded into memory but
126 /// before relocations are applied to the loaded sections. The object load
127 /// may have been initiated by MCJIT to resolve an external symbol for another
128 /// object that is being finalized. In that case, the object about which
129 /// the memory manager is being notified will be finalized immediately after
130 /// the memory manager returns from this call.
132 /// Memory managers which are preparing code for execution in an external
133 /// address space can use this call to remap the section addresses for the
134 /// newly loaded object.
135 virtual void notifyObjectLoaded(ExecutionEngine *EE,
136 const object::ObjectFile &) {}
138 /// This method is called when object loading is complete and section page
139 /// permissions can be applied. It is up to the memory manager implementation
140 /// to decide whether or not to act on this method. The memory manager will
141 /// typically allocate all sections as read-write and then apply specific
142 /// permissions when this method is called. Code sections cannot be executed
143 /// until this function has been called. In addition, any cache coherency
144 /// operations needed to reliably use the memory are also performed.
146 /// Returns true if an error occurred, false otherwise.
147 virtual bool finalizeMemory(std::string *ErrMsg = nullptr) = 0;
150 // Create wrappers for C Binding types (see CBindingWrapping.h).
151 DEFINE_SIMPLE_CONVERSION_FUNCTIONS(
152 RTDyldMemoryManager, LLVMMCJITMemoryManagerRef)