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/RuntimeDyld.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::finalizeMemory
37 /// directly. Clients of MCJIT should call MCJIT::finalizeObject.
38 class SectionMemoryManager : public RTDyldMemoryManager {
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 Update section-specific memory permissions and other attributes.
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. In addition, any cache coherency
71 /// operations needed to reliably use the memory are also performed.
73 /// \returns true if an error occurred, false otherwise.
74 virtual bool finalizeMemory(std::string *ErrMsg = 0);
76 void registerEHFrames(StringRef SectionData);
78 /// This method returns the address of the specified function. As such it is
79 /// only useful for resolving library symbols, not code generated symbols.
81 /// If \p AbortOnFailure is false and no function with the given name is
82 /// found, this function returns a null pointer. Otherwise, it prints a
83 /// message to stderr and aborts.
84 virtual void *getPointerToNamedFunction(const std::string &Name,
85 bool AbortOnFailure = true);
87 /// \brief Invalidate instruction cache for code sections.
89 /// Some platforms with separate data cache and instruction cache require
90 /// explicit cache flush, otherwise JIT code manipulations (like resolved
91 /// relocations) will get to the data cache but not to the instruction cache.
93 /// This method is called from finalizeMemory.
94 virtual void invalidateInstructionCache();
98 SmallVector<sys::MemoryBlock, 16> AllocatedMem;
99 SmallVector<sys::MemoryBlock, 16> FreeMem;
100 sys::MemoryBlock Near;
103 uint8_t *allocateSection(MemoryGroup &MemGroup, uintptr_t Size,
106 error_code applyMemoryGroupPermissions(MemoryGroup &MemGroup,
107 unsigned Permissions);
110 MemoryGroup RWDataMem;
111 MemoryGroup RODataMem;
116 #endif // LLVM_EXECUTION_ENGINE_SECTION_MEMORY_MANAGER_H