llvm-6502/include/llvm/Object/RelocVisitor.h
Tim Northover b05dc55460 AArch64: Add basic relocation processing for llvm-dwarfdump.
This allows llvm-dwarfdump to handle the relocations needed, at least
for LLVM-produced code.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@174874 91177308-0d34-0410-b5e6-96231b3b80d8
2013-02-11 11:16:02 +00:00

210 lines
6.3 KiB
C++

//===-- RelocVisitor.h - Visitor for object file relocations -*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file provides a wrapper around all the different types of relocations
// in different file formats, such that a client can handle them in a unified
// manner by only implementing a minimal number of functions.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_OBJECT_RELOCVISITOR_H
#define LLVM_OBJECT_RELOCVISITOR_H
#include "llvm/ADT/StringRef.h"
#include "llvm/Object/ObjectFile.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/ELF.h"
#include "llvm/Support/raw_ostream.h"
namespace llvm {
namespace object {
struct RelocToApply {
// The computed value after applying the relevant relocations.
int64_t Value;
// The width of the value; how many bytes to touch when applying the
// relocation.
char Width;
RelocToApply(const RelocToApply &In) : Value(In.Value), Width(In.Width) {}
RelocToApply(int64_t Value, char Width) : Value(Value), Width(Width) {}
RelocToApply() : Value(0), Width(0) {}
};
/// @brief Base class for object file relocation visitors.
class RelocVisitor {
public:
explicit RelocVisitor(StringRef FileFormat)
: FileFormat(FileFormat), HasError(false) {}
// TODO: Should handle multiple applied relocations via either passing in the
// previously computed value or just count paired relocations as a single
// visit.
RelocToApply visit(uint32_t RelocType, RelocationRef R, uint64_t SecAddr = 0,
uint64_t Value = 0) {
if (FileFormat == "ELF64-x86-64") {
switch (RelocType) {
case llvm::ELF::R_X86_64_NONE:
return visitELF_X86_64_NONE(R);
case llvm::ELF::R_X86_64_64:
return visitELF_X86_64_64(R, Value);
case llvm::ELF::R_X86_64_PC32:
return visitELF_X86_64_PC32(R, Value, SecAddr);
case llvm::ELF::R_X86_64_32:
return visitELF_X86_64_32(R, Value);
case llvm::ELF::R_X86_64_32S:
return visitELF_X86_64_32S(R, Value);
default:
HasError = true;
return RelocToApply();
}
} else if (FileFormat == "ELF32-i386") {
switch (RelocType) {
case llvm::ELF::R_386_NONE:
return visitELF_386_NONE(R);
case llvm::ELF::R_386_32:
return visitELF_386_32(R, Value);
case llvm::ELF::R_386_PC32:
return visitELF_386_PC32(R, Value, SecAddr);
default:
HasError = true;
return RelocToApply();
}
} else if (FileFormat == "ELF64-ppc64") {
switch (RelocType) {
case llvm::ELF::R_PPC64_ADDR32:
return visitELF_PPC64_ADDR32(R, Value);
default:
HasError = true;
return RelocToApply();
}
} else if (FileFormat == "ELF32-mips") {
switch (RelocType) {
case llvm::ELF::R_MIPS_32:
return visitELF_MIPS_32(R, Value);
default:
HasError = true;
return RelocToApply();
}
} else if (FileFormat == "ELF64-aarch64") {
switch (RelocType) {
case llvm::ELF::R_AARCH64_ABS32:
return visitELF_AARCH64_ABS32(R, Value);
case llvm::ELF::R_AARCH64_ABS64:
return visitELF_AARCH64_ABS64(R, Value);
default:
HasError = true;
return RelocToApply();
}
}
HasError = true;
return RelocToApply();
}
bool error() { return HasError; }
private:
StringRef FileFormat;
bool HasError;
/// Operations
/// 386-ELF
RelocToApply visitELF_386_NONE(RelocationRef R) {
return RelocToApply(0, 0);
}
// Ideally the Addend here will be the addend in the data for
// the relocation. It's not actually the case for Rel relocations.
RelocToApply visitELF_386_32(RelocationRef R, uint64_t Value) {
int64_t Addend;
R.getAdditionalInfo(Addend);
return RelocToApply(Value + Addend, 4);
}
RelocToApply visitELF_386_PC32(RelocationRef R, uint64_t Value,
uint64_t SecAddr) {
int64_t Addend;
R.getAdditionalInfo(Addend);
uint64_t Address;
R.getAddress(Address);
return RelocToApply(Value + Addend - Address, 4);
}
/// X86-64 ELF
RelocToApply visitELF_X86_64_NONE(RelocationRef R) {
return RelocToApply(0, 0);
}
RelocToApply visitELF_X86_64_64(RelocationRef R, uint64_t Value) {
int64_t Addend;
R.getAdditionalInfo(Addend);
return RelocToApply(Value + Addend, 8);
}
RelocToApply visitELF_X86_64_PC32(RelocationRef R, uint64_t Value,
uint64_t SecAddr) {
int64_t Addend;
R.getAdditionalInfo(Addend);
uint64_t Address;
R.getAddress(Address);
return RelocToApply(Value + Addend - Address, 4);
}
RelocToApply visitELF_X86_64_32(RelocationRef R, uint64_t Value) {
int64_t Addend;
R.getAdditionalInfo(Addend);
uint32_t Res = (Value + Addend) & 0xFFFFFFFF;
return RelocToApply(Res, 4);
}
RelocToApply visitELF_X86_64_32S(RelocationRef R, uint64_t Value) {
int64_t Addend;
R.getAdditionalInfo(Addend);
int32_t Res = (Value + Addend) & 0xFFFFFFFF;
return RelocToApply(Res, 4);
}
/// PPC64 ELF
RelocToApply visitELF_PPC64_ADDR32(RelocationRef R, uint64_t Value) {
int64_t Addend;
R.getAdditionalInfo(Addend);
uint32_t Res = (Value + Addend) & 0xFFFFFFFF;
return RelocToApply(Res, 4);
}
/// MIPS ELF
RelocToApply visitELF_MIPS_32(RelocationRef R, uint64_t Value) {
int64_t Addend;
R.getAdditionalInfo(Addend);
uint32_t Res = (Value + Addend) & 0xFFFFFFFF;
return RelocToApply(Res, 4);
}
// AArch64 ELF
RelocToApply visitELF_AARCH64_ABS32(RelocationRef R, uint64_t Value) {
int64_t Addend;
R.getAdditionalInfo(Addend);
int64_t Res = Value + Addend;
// Overflow check allows for both signed and unsigned interpretation.
if (Res < INT32_MIN || Res > UINT32_MAX)
HasError = true;
return RelocToApply(static_cast<uint32_t>(Res), 4);
}
RelocToApply visitELF_AARCH64_ABS64(RelocationRef R, uint64_t Value) {
int64_t Addend;
R.getAdditionalInfo(Addend);
return RelocToApply(Value + Addend, 8);
}
};
}
}
#endif