1//===- ARMToARMStub.cpp ---------------------------------------------------===// 2// 3// The MCLinker Project 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9 10#include "ARMToARMStub.h" 11#include "ARMLDBackend.h" 12 13#include "mcld/Fragment/Relocation.h" 14#include "mcld/LD/LDSymbol.h" 15#include "mcld/LD/ResolveInfo.h" 16 17#include <llvm/Support/ELF.h> 18 19namespace mcld { 20 21//===----------------------------------------------------------------------===// 22// ARMToARMStub 23//===----------------------------------------------------------------------===// 24const uint32_t ARMToARMStub::PIC_TEMPLATE[] = { 25 0xe59fc000, // ldr r12, [pc] 26 0xe08ff00c, // add pc, pc, ip 27 0x0 // dcd R_ARM_REL32(X-4) 28}; 29 30const uint32_t ARMToARMStub::TEMPLATE[] = { 31 0xe51ff004, // ldr pc, [pc, #-4] 32 0x0 // dcd R_ARM_ABS32(X) 33}; 34 35ARMToARMStub::ARMToARMStub(bool pIsOutputPIC) 36 : m_pData(NULL), m_Name("A2A_prototype"), m_Size(0x0) { 37 if (pIsOutputPIC) { 38 m_pData = PIC_TEMPLATE; 39 m_Size = sizeof(PIC_TEMPLATE); 40 addFixup(8u, -4, llvm::ELF::R_ARM_REL32); 41 } else { 42 m_pData = TEMPLATE; 43 m_Size = sizeof(TEMPLATE); 44 addFixup(4u, 0x0, llvm::ELF::R_ARM_ABS32); 45 } 46} 47 48/// for doClone 49ARMToARMStub::ARMToARMStub(const uint32_t* pData, 50 size_t pSize, 51 const_fixup_iterator pBegin, 52 const_fixup_iterator pEnd) 53 : m_pData(pData), m_Name("A2A_veneer"), m_Size(pSize) { 54 for (const_fixup_iterator it = pBegin, ie = pEnd; it != ie; ++it) 55 addFixup(**it); 56} 57 58ARMToARMStub::~ARMToARMStub() { 59} 60 61bool ARMToARMStub::isMyDuty(const class Relocation& pReloc, 62 uint64_t pSource, 63 uint64_t pTargetSymValue) const { 64 bool result = false; 65 // Check if the branch target is ARM 66 if ((pTargetSymValue & 0x1) == 0x0) { 67 switch (pReloc.type()) { 68 case llvm::ELF::R_ARM_PC24: 69 case llvm::ELF::R_ARM_CALL: 70 case llvm::ELF::R_ARM_JUMP24: 71 case llvm::ELF::R_ARM_PLT32: { 72 // Check if the branch target is too far 73 uint64_t dest = pTargetSymValue + pReloc.addend() + 8u; 74 int64_t branch_offset = static_cast<int64_t>(dest) - pSource; 75 if ((branch_offset > ARMGNULDBackend::ARM_MAX_FWD_BRANCH_OFFSET) || 76 (branch_offset < ARMGNULDBackend::ARM_MAX_BWD_BRANCH_OFFSET)) { 77 result = true; 78 } 79 break; 80 } 81 default: 82 break; 83 } 84 } 85 return result; 86} 87 88const std::string& ARMToARMStub::name() const { 89 return m_Name; 90} 91 92const uint8_t* ARMToARMStub::getContent() const { 93 return reinterpret_cast<const uint8_t*>(m_pData); 94} 95 96size_t ARMToARMStub::size() const { 97 return m_Size; 98} 99 100size_t ARMToARMStub::alignment() const { 101 return 4u; 102} 103 104Stub* ARMToARMStub::doClone() { 105 return new ARMToARMStub(m_pData, m_Size, fixup_begin(), fixup_end()); 106} 107 108} // namespace mcld 109