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//===- ARMToARMStub.cpp ---------------------------------------------------===//
//
// The MCLinker Project
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#include "ARMToARMStub.h"
#include "ARMLDBackend.h"
#include "mcld/Fragment/Relocation.h"
#include "mcld/LD/LDSymbol.h"
#include "mcld/LD/ResolveInfo.h"
#include <llvm/Support/ELF.h>
namespace mcld {
//===----------------------------------------------------------------------===//
// ARMToARMStub
//===----------------------------------------------------------------------===//
const uint32_t ARMToARMStub::PIC_TEMPLATE[] = {
0xe59fc000, // ldr r12, [pc]
0xe08ff00c, // add pc, pc, ip
0x0 // dcd R_ARM_REL32(X-4)
};
const uint32_t ARMToARMStub::TEMPLATE[] = {
0xe51ff004, // ldr pc, [pc, #-4]
0x0 // dcd R_ARM_ABS32(X)
};
ARMToARMStub::ARMToARMStub(bool pIsOutputPIC)
: m_pData(NULL), m_Name("A2A_prototype"), m_Size(0x0) {
if (pIsOutputPIC) {
m_pData = PIC_TEMPLATE;
m_Size = sizeof(PIC_TEMPLATE);
addFixup(8u, -4, llvm::ELF::R_ARM_REL32);
} else {
m_pData = TEMPLATE;
m_Size = sizeof(TEMPLATE);
addFixup(4u, 0x0, llvm::ELF::R_ARM_ABS32);
}
}
/// for doClone
ARMToARMStub::ARMToARMStub(const uint32_t* pData,
size_t pSize,
const_fixup_iterator pBegin,
const_fixup_iterator pEnd)
: m_pData(pData), m_Name("A2A_veneer"), m_Size(pSize) {
for (const_fixup_iterator it = pBegin, ie = pEnd; it != ie; ++it)
addFixup(**it);
}
ARMToARMStub::~ARMToARMStub() {
}
bool ARMToARMStub::isMyDuty(const class Relocation& pReloc,
uint64_t pSource,
uint64_t pTargetSymValue) const {
bool result = false;
// Check if the branch target is ARM
if ((pTargetSymValue & 0x1) == 0x0) {
switch (pReloc.type()) {
case llvm::ELF::R_ARM_PC24:
case llvm::ELF::R_ARM_CALL:
case llvm::ELF::R_ARM_JUMP24:
case llvm::ELF::R_ARM_PLT32: {
// Check if the branch target is too far
uint64_t dest = pTargetSymValue + pReloc.addend() + 8u;
int64_t branch_offset = static_cast<int64_t>(dest) - pSource;
if ((branch_offset > ARMGNULDBackend::ARM_MAX_FWD_BRANCH_OFFSET) ||
(branch_offset < ARMGNULDBackend::ARM_MAX_BWD_BRANCH_OFFSET)) {
result = true;
}
break;
}
default:
break;
}
}
return result;
}
const std::string& ARMToARMStub::name() const {
return m_Name;
}
const uint8_t* ARMToARMStub::getContent() const {
return reinterpret_cast<const uint8_t*>(m_pData);
}
size_t ARMToARMStub::size() const {
return m_Size;
}
size_t ARMToARMStub::alignment() const {
return 4u;
}
Stub* ARMToARMStub::doClone() {
return new ARMToARMStub(m_pData, m_Size, fixup_begin(), fixup_end());
}
} // namespace mcld