llvm-6502/include/llvm/ExecutionEngine/RuntimeDyld.h
Lang Hames 20425d92df Add an option to MCJIT to have it forward all sections to the
RTDyldMemoryManager, regardless of whether it thinks they're "required for
execution".

Currently, RuntimeDyld only passes sections that are "required for execution"
to the RTDyldMemoryManager, and takes "required for execution" to mean exactly
"contains symbols or relocations". There are two problems with this:
(1) It can drop sections with anonymous data that is referenced by code.
(2) It leaves the JIT client no way to inspect interesting sections that aren't
    actually required to run the program (e.g dwarf sections).

A test case is still in the works.

Future work: We may want to replace this with a generic section filtering
mechanism, but that will require more consideration. For now, this flag at least
allows clients to volunteer to do the filtering themselves.

Fixes <rdar://problem/15177691>.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204398 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-20 21:06:46 +00:00

106 lines
4.1 KiB
C++

//===-- 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 "llvm/ADT/StringRef.h"
#include "llvm/ExecutionEngine/ObjectBuffer.h"
#include "llvm/ExecutionEngine/RTDyldMemoryManager.h"
#include "llvm/Support/Memory.h"
namespace llvm {
namespace object {
class ObjectFile;
}
class RuntimeDyldImpl;
class ObjectImage;
class RuntimeDyld {
RuntimeDyld(const RuntimeDyld &) LLVM_DELETED_FUNCTION;
void operator=(const RuntimeDyld &) LLVM_DELETED_FUNCTION;
// RuntimeDyldImpl is the actual class. RuntimeDyld is just the public
// interface.
RuntimeDyldImpl *Dyld;
RTDyldMemoryManager *MM;
bool ProcessAllSections;
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:
RuntimeDyld(RTDyldMemoryManager *);
~RuntimeDyld();
/// Prepare the object contained in the input buffer for execution.
/// Ownership of the input buffer is transferred to the ObjectImage
/// instance returned from this function if successful. In the case of load
/// failure, the input buffer will be deleted.
ObjectImage *loadObject(ObjectBuffer *InputBuffer);
/// Prepare the referenced object file for execution.
/// Ownership of the input object is transferred to the ObjectImage
/// instance returned from this function if successful. In the case of load
/// failure, the input object will be deleted.
ObjectImage *loadObject(object::ObjectFile *InputObject);
/// 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 *getSymbolAddress(StringRef Name);
/// Get the address of the target copy of the symbol. This is the address
/// used for relocation.
uint64_t getSymbolLoadAddress(StringRef Name);
/// 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();
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;
}
};
} // end namespace llvm
#endif