+ /// \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);