forked from OSchip/llvm-project
62 lines
2.0 KiB
C++
62 lines
2.0 KiB
C++
//===- Memory.h -------------------------------------------------*- C++ -*-===//
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//
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// The LLVM Linker
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//
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// This file is distributed under the University of Illinois Open Source
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// License. See LICENSE.TXT for details.
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//
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//===----------------------------------------------------------------------===//
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//
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// This file defines arena allocators.
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//
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// Almost all large objects, such as files, sections or symbols, are
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// used for the entire lifetime of the linker once they are created.
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// This usage characteristic makes arena allocator an attractive choice
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// where the entire linker is one arena. With an arena, newly created
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// objects belong to the arena and freed all at once when everything is done.
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// Arena allocators are efficient and easy to understand.
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// Most objects are allocated using the arena allocators defined by this file.
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//
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//===----------------------------------------------------------------------===//
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#ifndef LLD_ELF_MEMORY_H
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#define LLD_ELF_MEMORY_H
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#include "llvm/Support/Allocator.h"
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#include "llvm/Support/StringSaver.h"
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#include <vector>
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namespace lld {
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namespace elf {
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// Use this arena if your object doesn't have a destructor.
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extern llvm::BumpPtrAllocator BAlloc;
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extern llvm::StringSaver Saver;
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// These two classes are hack to keep track of all
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// SpecificBumpPtrAllocator instances.
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struct SpecificAllocBase {
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SpecificAllocBase();
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virtual ~SpecificAllocBase() = default;
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virtual void reset() = 0;
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static std::vector<SpecificAllocBase *> Instances;
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};
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template <class T> struct SpecificAlloc : public SpecificAllocBase {
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void reset() override { Alloc.DestroyAll(); }
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llvm::SpecificBumpPtrAllocator<T> Alloc;
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};
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// Use this arena if your object has a destructor.
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// Your destructor will be invoked from freeArena().
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template <typename T, typename... U> inline T *make(U &&... Args) {
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static SpecificAlloc<T> Alloc;
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return new (Alloc.Alloc.Allocate()) T(std::forward<U>(Args)...);
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}
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void freeArena();
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}
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}
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#endif
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