1 //===- SectionMemoryManager.h - Memory manager for MCJIT/RtDyld -*- 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 // This file contains the declaration of a section-based memory manager used by
11 // the MCJIT execution engine and RuntimeDyld.
13 //===----------------------------------------------------------------------===//
15 #ifndef LLVM_EXECUTIONENGINE_SECTIONMEMORYMANAGER_H
16 #define LLVM_EXECUTIONENGINE_SECTIONMEMORYMANAGER_H
18 #include "llvm/ADT/SmallVector.h"
19 #include "llvm/ExecutionEngine/JITMemoryManager.h"
20 #include "llvm/Support/ErrorHandling.h"
21 #include "llvm/Support/Memory.h"
25 /// This is a simple memory manager which implements the methods called by
26 /// the RuntimeDyld class to allocate memory for section-based loading of
27 /// objects, usually those generated by the MCJIT execution engine.
29 /// This memory manager allocates all section memory as read-write. The
30 /// RuntimeDyld will copy JITed section memory into these allocated blocks
31 /// and perform any necessary linking and relocations.
33 /// Any client using this memory manager MUST ensure that section-specific
34 /// page permissions have been applied before attempting to execute functions
35 /// in the JITed object. Permissions can be applied either by calling
36 /// MCJIT::finalizeObject or by calling SectionMemoryManager::applyPermissions
37 /// directly. Clients of MCJIT should call MCJIT::finalizeObject.
38 class SectionMemoryManager : public JITMemoryManager {
39 SectionMemoryManager(const SectionMemoryManager&) LLVM_DELETED_FUNCTION;
40 void operator=(const SectionMemoryManager&) LLVM_DELETED_FUNCTION;
43 SectionMemoryManager() { }
44 virtual ~SectionMemoryManager();
46 /// \brief Allocates a memory block of (at least) the given size suitable for
49 /// The value of \p Alignment must be a power of two. If \p Alignment is zero
50 /// a default alignment of 16 will be used.
51 virtual uint8_t *allocateCodeSection(uintptr_t Size, unsigned Alignment,
54 /// \brief Allocates a memory block of (at least) the given size suitable for
57 /// The value of \p Alignment must be a power of two. If \p Alignment is zero
58 /// a default alignment of 16 will be used.
59 virtual uint8_t *allocateDataSection(uintptr_t Size, unsigned Alignment,
63 /// \brief Applies section-specific memory permissions.
65 /// This method is called when object loading is complete and section page
66 /// permissions can be applied. It is up to the memory manager implementation
67 /// to decide whether or not to act on this method. The memory manager will
68 /// typically allocate all sections as read-write and then apply specific
69 /// permissions when this method is called. Code sections cannot be executed
70 /// until this function has been called.
72 /// \returns true if an error occurred, false otherwise.
73 virtual bool applyPermissions(std::string *ErrMsg = 0);
75 /// This method returns the address of the specified function. As such it is
76 /// only useful for resolving library symbols, not code generated symbols.
78 /// If \p AbortOnFailure is false and no function with the given name is
79 /// found, this function returns a null pointer. Otherwise, it prints a
80 /// message to stderr and aborts.
81 virtual void *getPointerToNamedFunction(const std::string &Name,
82 bool AbortOnFailure = true);
84 /// \brief Invalidate instruction cache for code sections.
86 /// Some platforms with separate data cache and instruction cache require
87 /// explicit cache flush, otherwise JIT code manipulations (like resolved
88 /// relocations) will get to the data cache but not to the instruction cache.
90 /// This method is called from applyPermissions.
91 virtual void invalidateInstructionCache();
95 SmallVector<sys::MemoryBlock, 16> AllocatedMem;
96 SmallVector<sys::MemoryBlock, 16> FreeMem;
97 sys::MemoryBlock Near;
100 uint8_t *allocateSection(MemoryGroup &MemGroup, uintptr_t Size,
103 error_code applyMemoryGroupPermissions(MemoryGroup &MemGroup,
104 unsigned Permissions);
107 MemoryGroup RWDataMem;
108 MemoryGroup RODataMem;
112 /// Functions below are not used by MCJIT or RuntimeDyld, but must be
113 /// implemented because they are declared as pure virtuals in the base class.
116 virtual void setMemoryWritable() {
117 llvm_unreachable("Unexpected call!");
119 virtual void setMemoryExecutable() {
120 llvm_unreachable("Unexpected call!");
122 virtual void setPoisonMemory(bool poison) {
123 llvm_unreachable("Unexpected call!");
125 virtual void AllocateGOT() {
126 llvm_unreachable("Unexpected call!");
128 virtual uint8_t *getGOTBase() const {
129 llvm_unreachable("Unexpected call!");
132 virtual uint8_t *startFunctionBody(const Function *F,
133 uintptr_t &ActualSize){
134 llvm_unreachable("Unexpected call!");
137 virtual uint8_t *allocateStub(const GlobalValue *F, unsigned StubSize,
138 unsigned Alignment) {
139 llvm_unreachable("Unexpected call!");
142 virtual void endFunctionBody(const Function *F, uint8_t *FunctionStart,
143 uint8_t *FunctionEnd) {
144 llvm_unreachable("Unexpected call!");
146 virtual uint8_t *allocateSpace(intptr_t Size, unsigned Alignment) {
147 llvm_unreachable("Unexpected call!");
150 virtual uint8_t *allocateGlobal(uintptr_t Size, unsigned Alignment) {
151 llvm_unreachable("Unexpected call!");
154 virtual void deallocateFunctionBody(void *Body) {
155 llvm_unreachable("Unexpected call!");
157 virtual uint8_t *startExceptionTable(const Function *F,
158 uintptr_t &ActualSize) {
159 llvm_unreachable("Unexpected call!");
162 virtual void endExceptionTable(const Function *F, uint8_t *TableStart,
163 uint8_t *TableEnd, uint8_t *FrameRegister) {
164 llvm_unreachable("Unexpected call!");
166 virtual void deallocateExceptionTable(void *ET) {
167 llvm_unreachable("Unexpected call!");
173 #endif // LLVM_EXECUTION_ENGINE_SECTION_MEMORY_MANAGER_H