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,
53 StringRef SectionName);
55 /// \brief Allocates a memory block of (at least) the given size suitable for
58 /// The value of \p Alignment must be a power of two. If \p Alignment is zero
59 /// a default alignment of 16 will be used.
60 virtual uint8_t *allocateDataSection(uintptr_t Size, unsigned Alignment,
62 StringRef SectionName,
65 /// \brief Update section-specific memory permissions and other attributes.
67 /// This method is called when object loading is complete and section page
68 /// permissions can be applied. It is up to the memory manager implementation
69 /// to decide whether or not to act on this method. The memory manager will
70 /// typically allocate all sections as read-write and then apply specific
71 /// permissions when this method is called. Code sections cannot be executed
72 /// until this function has been called. In addition, any cache coherency
73 /// operations needed to reliably use the memory are also performed.
75 /// \returns true if an error occurred, false otherwise.
76 virtual bool finalizeMemory(std::string *ErrMsg = 0);
78 /// \brief Invalidate instruction cache for code sections.
80 /// Some platforms with separate data cache and instruction cache require
81 /// explicit cache flush, otherwise JIT code manipulations (like resolved
82 /// relocations) will get to the data cache but not to the instruction cache.
84 /// This method is called from finalizeMemory.
85 virtual void invalidateInstructionCache();
89 SmallVector<sys::MemoryBlock, 16> AllocatedMem;
90 SmallVector<sys::MemoryBlock, 16> FreeMem;
91 sys::MemoryBlock Near;
94 uint8_t *allocateSection(MemoryGroup &MemGroup, uintptr_t Size,
97 error_code applyMemoryGroupPermissions(MemoryGroup &MemGroup,
98 unsigned Permissions);
101 MemoryGroup RWDataMem;
102 MemoryGroup RODataMem;
107 #endif // LLVM_EXECUTION_ENGINE_SECTION_MEMORY_MANAGER_H