| //===-- RuntimeDyld.h - Run-time dynamic linker for MC-JIT ------*- C++ -*-===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file is distributed under the University of Illinois Open Source |
| // License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // Interface for the runtime dynamic linker facilities of the MC-JIT. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #ifndef LLVM_EXECUTIONENGINE_RUNTIMEDYLD_H |
| #define LLVM_EXECUTIONENGINE_RUNTIMEDYLD_H |
| |
| #include "JITSymbolFlags.h" |
| #include "llvm/ADT/StringRef.h" |
| #include "llvm/Support/Memory.h" |
| #include <memory> |
| |
| namespace llvm { |
| |
| namespace object { |
| class ObjectFile; |
| template <typename T> class OwningBinary; |
| } |
| |
| class RuntimeDyldImpl; |
| class RuntimeDyldCheckerImpl; |
| |
| class RuntimeDyld { |
| friend class RuntimeDyldCheckerImpl; |
| |
| RuntimeDyld(const RuntimeDyld &) = delete; |
| void operator=(const RuntimeDyld &) = delete; |
| |
| protected: |
| // Change the address associated with a section when resolving relocations. |
| // Any relocations already associated with the symbol will be re-resolved. |
| void reassignSectionAddress(unsigned SectionID, uint64_t Addr); |
| public: |
| |
| /// \brief Information about a named symbol. |
| class SymbolInfo : public JITSymbolBase { |
| public: |
| SymbolInfo(std::nullptr_t) : JITSymbolBase(JITSymbolFlags::None), Address(0) {} |
| SymbolInfo(uint64_t Address, JITSymbolFlags Flags) |
| : JITSymbolBase(Flags), Address(Address) {} |
| explicit operator bool() const { return Address != 0; } |
| uint64_t getAddress() const { return Address; } |
| private: |
| uint64_t Address; |
| }; |
| |
| /// \brief Information about the loaded object. |
| class LoadedObjectInfo { |
| friend class RuntimeDyldImpl; |
| public: |
| LoadedObjectInfo(RuntimeDyldImpl &RTDyld, unsigned BeginIdx, |
| unsigned EndIdx) |
| : RTDyld(RTDyld), BeginIdx(BeginIdx), EndIdx(EndIdx) { } |
| |
| virtual ~LoadedObjectInfo() {} |
| |
| virtual object::OwningBinary<object::ObjectFile> |
| getObjectForDebug(const object::ObjectFile &Obj) const = 0; |
| |
| uint64_t getSectionLoadAddress(StringRef Name) const; |
| |
| protected: |
| virtual void anchor(); |
| |
| RuntimeDyldImpl &RTDyld; |
| unsigned BeginIdx, EndIdx; |
| }; |
| |
| /// \brief Memory Management. |
| class MemoryManager { |
| public: |
| virtual ~MemoryManager() {}; |
| |
| /// Allocate a memory block of (at least) the given size suitable for |
| /// executable code. The SectionID is a unique identifier assigned by the |
| /// RuntimeDyld instance, and optionally recorded by the memory manager to |
| /// access a loaded section. |
| virtual uint8_t *allocateCodeSection(uintptr_t Size, unsigned Alignment, |
| unsigned SectionID, |
| StringRef SectionName) = 0; |
| |
| /// Allocate a memory block of (at least) the given size suitable for data. |
| /// The SectionID is a unique identifier assigned by the JIT engine, and |
| /// optionally recorded by the memory manager to access a loaded section. |
| virtual uint8_t *allocateDataSection(uintptr_t Size, unsigned Alignment, |
| unsigned SectionID, |
| StringRef SectionName, |
| bool IsReadOnly) = 0; |
| |
| /// Inform the memory manager about the total amount of memory required to |
| /// allocate all sections to be loaded: |
| /// \p CodeSize - the total size of all code sections |
| /// \p DataSizeRO - the total size of all read-only data sections |
| /// \p DataSizeRW - the total size of all read-write data sections |
| /// |
| /// Note that by default the callback is disabled. To enable it |
| /// redefine the method needsToReserveAllocationSpace to return true. |
| virtual void reserveAllocationSpace(uintptr_t CodeSize, |
| uintptr_t DataSizeRO, |
| uintptr_t DataSizeRW) {} |
| |
| /// Override to return true to enable the reserveAllocationSpace callback. |
| virtual bool needsToReserveAllocationSpace() { return false; } |
| |
| /// Register the EH frames with the runtime so that c++ exceptions work. |
| /// |
| /// \p Addr parameter provides the local address of the EH frame section |
| /// data, while \p LoadAddr provides the address of the data in the target |
| /// address space. If the section has not been remapped (which will usually |
| /// be the case for local execution) these two values will be the same. |
| virtual void registerEHFrames(uint8_t *Addr, uint64_t LoadAddr, |
| size_t Size) = 0; |
| virtual void deregisterEHFrames(uint8_t *addr, uint64_t LoadAddr, |
| size_t Size) = 0; |
| |
| /// This method is called when object loading is complete and section page |
| /// permissions can be applied. It is up to the memory manager implementation |
| /// to decide whether or not to act on this method. The memory manager will |
| /// typically allocate all sections as read-write and then apply specific |
| /// permissions when this method is called. Code sections cannot be executed |
| /// until this function has been called. In addition, any cache coherency |
| /// operations needed to reliably use the memory are also performed. |
| /// |
| /// Returns true if an error occurred, false otherwise. |
| virtual bool finalizeMemory(std::string *ErrMsg = nullptr) = 0; |
| |
| private: |
| virtual void anchor(); |
| }; |
| |
| /// \brief Symbol resolution. |
| class SymbolResolver { |
| public: |
| virtual ~SymbolResolver() {}; |
| |
| /// This method returns the address of the specified function or variable. |
| /// It is used to resolve symbols during module linking. |
| virtual SymbolInfo findSymbol(const std::string &Name) = 0; |
| |
| /// This method returns the address of the specified symbol if it exists |
| /// within the logical dynamic library represented by this |
| /// RTDyldMemoryManager. Unlike getSymbolAddress, queries through this |
| /// interface should return addresses for hidden symbols. |
| /// |
| /// This is of particular importance for the Orc JIT APIs, which support lazy |
| /// compilation by breaking up modules: Each of those broken out modules |
| /// must be able to resolve hidden symbols provided by the others. Clients |
| /// writing memory managers for MCJIT can usually ignore this method. |
| /// |
| /// This method will be queried by RuntimeDyld when checking for previous |
| /// definitions of common symbols. It will *not* be queried by default when |
| /// resolving external symbols (this minimises the link-time overhead for |
| /// MCJIT clients who don't care about Orc features). If you are writing a |
| /// RTDyldMemoryManager for Orc and want "external" symbol resolution to |
| /// search the logical dylib, you should override your getSymbolAddress |
| /// method call this method directly. |
| virtual SymbolInfo findSymbolInLogicalDylib(const std::string &Name) = 0; |
| private: |
| virtual void anchor(); |
| }; |
| |
| /// \brief Construct a RuntimeDyld instance. |
| RuntimeDyld(MemoryManager &MemMgr, SymbolResolver &Resolver); |
| ~RuntimeDyld(); |
| |
| /// Add the referenced object file to the list of objects to be loaded and |
| /// relocated. |
| std::unique_ptr<LoadedObjectInfo> loadObject(const object::ObjectFile &O); |
| |
| /// Get the address of our local copy of the symbol. This may or may not |
| /// be the address used for relocation (clients can copy the data around |
| /// and resolve relocatons based on where they put it). |
| void *getSymbolLocalAddress(StringRef Name) const; |
| |
| /// Get the target address and flags for the named symbol. |
| /// This address is the one used for relocation. |
| SymbolInfo getSymbol(StringRef Name) const; |
| |
| /// Resolve the relocations for all symbols we currently know about. |
| void resolveRelocations(); |
| |
| /// Map a section to its target address space value. |
| /// Map the address of a JIT section as returned from the memory manager |
| /// to the address in the target process as the running code will see it. |
| /// This is the address which will be used for relocation resolution. |
| void mapSectionAddress(const void *LocalAddress, uint64_t TargetAddress); |
| |
| /// Register any EH frame sections that have been loaded but not previously |
| /// registered with the memory manager. Note, RuntimeDyld is responsible |
| /// for identifying the EH frame and calling the memory manager with the |
| /// EH frame section data. However, the memory manager itself will handle |
| /// the actual target-specific EH frame registration. |
| void registerEHFrames(); |
| |
| void deregisterEHFrames(); |
| |
| bool hasError(); |
| StringRef getErrorString(); |
| |
| /// By default, only sections that are "required for execution" are passed to |
| /// the RTDyldMemoryManager, and other sections are discarded. Passing 'true' |
| /// to this method will cause RuntimeDyld to pass all sections to its |
| /// memory manager regardless of whether they are "required to execute" in the |
| /// usual sense. This is useful for inspecting metadata sections that may not |
| /// contain relocations, E.g. Debug info, stackmaps. |
| /// |
| /// Must be called before the first object file is loaded. |
| void setProcessAllSections(bool ProcessAllSections) { |
| assert(!Dyld && "setProcessAllSections must be called before loadObject."); |
| this->ProcessAllSections = ProcessAllSections; |
| } |
| |
| private: |
| // RuntimeDyldImpl is the actual class. RuntimeDyld is just the public |
| // interface. |
| std::unique_ptr<RuntimeDyldImpl> Dyld; |
| MemoryManager &MemMgr; |
| SymbolResolver &Resolver; |
| bool ProcessAllSections; |
| RuntimeDyldCheckerImpl *Checker; |
| }; |
| |
| } // end namespace llvm |
| |
| #endif |