1 //===- THMToTHMStub.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 "THMToTHMStub.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
19 namespace mcld {
20
21 //===----------------------------------------------------------------------===//
22 // THMToTHMStub
23 //===----------------------------------------------------------------------===//
24 const uint32_t THMToTHMStub::PIC_TEMPLATE[] = {
25 0x46c04778, // bx pc ... nop
26 0xe59fc004, // ldr r12, [pc, #4]
27 0xe08fc00c, // add ip, pc, ip
28 0xe12fff1c, // bx ip
29 0x0 // dcd R_ARM_REL32(X)
30 };
31
32 const uint32_t THMToTHMStub::TEMPLATE[] = {
33 0x46c04778, // bx pc ... nop
34 0xe59fc000, // ldr ip, [pc, #0]
35 0xe12fff1c, // bx ip
36 0x0 // dcd R_ARM_ABS32(X)
37 };
38
THMToTHMStub(bool pIsOutputPIC,bool pUsingThumb2)39 THMToTHMStub::THMToTHMStub(bool pIsOutputPIC, bool pUsingThumb2)
40 : m_pData(NULL),
41 m_Name("T2T_prototype"),
42 m_Size(0x0),
43 m_bUsingThumb2(pUsingThumb2) {
44 if (pIsOutputPIC) {
45 m_pData = PIC_TEMPLATE;
46 m_Size = sizeof(PIC_TEMPLATE);
47 addFixup(16u, 0x0, llvm::ELF::R_ARM_REL32);
48 } else {
49 m_pData = TEMPLATE;
50 m_Size = sizeof(TEMPLATE);
51 addFixup(12u, 0x0, llvm::ELF::R_ARM_ABS32);
52 }
53 }
54
55 /// for doClone
THMToTHMStub(const uint32_t * pData,size_t pSize,const_fixup_iterator pBegin,const_fixup_iterator pEnd,bool pUsingThumb2)56 THMToTHMStub::THMToTHMStub(const uint32_t* pData,
57 size_t pSize,
58 const_fixup_iterator pBegin,
59 const_fixup_iterator pEnd,
60 bool pUsingThumb2)
61 : m_pData(pData),
62 m_Name("T2T_veneer"),
63 m_Size(pSize),
64 m_bUsingThumb2(pUsingThumb2) {
65 for (const_fixup_iterator it = pBegin, ie = pEnd; it != ie; ++it)
66 addFixup(**it);
67 }
68
~THMToTHMStub()69 THMToTHMStub::~THMToTHMStub() {
70 }
71
isMyDuty(const class Relocation & pReloc,uint64_t pSource,uint64_t pTargetSymValue) const72 bool THMToTHMStub::isMyDuty(const class Relocation& pReloc,
73 uint64_t pSource,
74 uint64_t pTargetSymValue) const {
75 bool result = false;
76 // Check if the branch target is THUMB
77 if ((pTargetSymValue & 0x1) != 0x0) {
78 switch (pReloc.type()) {
79 case llvm::ELF::R_ARM_THM_CALL:
80 case llvm::ELF::R_ARM_THM_JUMP24: {
81 // Check if the branch target is too far
82 uint64_t dest = pTargetSymValue + pReloc.addend() + 4u;
83 int64_t branch_offset = static_cast<int64_t>(dest) - pSource;
84 if (m_bUsingThumb2) {
85 if ((branch_offset > ARMGNULDBackend::THM2_MAX_FWD_BRANCH_OFFSET) ||
86 (branch_offset < ARMGNULDBackend::THM2_MAX_BWD_BRANCH_OFFSET)) {
87 result = true;
88 break;
89 }
90 } else {
91 if ((branch_offset > ARMGNULDBackend::THM_MAX_FWD_BRANCH_OFFSET) ||
92 (branch_offset < ARMGNULDBackend::THM_MAX_BWD_BRANCH_OFFSET)) {
93 result = true;
94 break;
95 }
96 }
97 break;
98 }
99 default:
100 break;
101 }
102 }
103 return result;
104 }
105
name() const106 const std::string& THMToTHMStub::name() const {
107 return m_Name;
108 }
109
getContent() const110 const uint8_t* THMToTHMStub::getContent() const {
111 return reinterpret_cast<const uint8_t*>(m_pData);
112 }
113
size() const114 size_t THMToTHMStub::size() const {
115 return m_Size;
116 }
117
alignment() const118 size_t THMToTHMStub::alignment() const {
119 return 4u;
120 }
121
initSymValue() const122 uint64_t THMToTHMStub::initSymValue() const {
123 return 0x1;
124 }
125
doClone()126 Stub* THMToTHMStub::doClone() {
127 return new THMToTHMStub(
128 m_pData, m_Size, fixup_begin(), fixup_end(), m_bUsingThumb2);
129 }
130
131 } // namespace mcld
132