1//===- ARM64_32.cpp
2//----------------------------------------------------------===//
3//
4// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
5// See https://llvm.org/LICENSE.txt for license information.
6// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7//
8//===----------------------------------------------------------------------===//
9
10#include "Arch/ARM64Common.h"
11#include "InputFiles.h"
12#include "Symbols.h"
13#include "SyntheticSections.h"
14#include "Target.h"
15
16#include "lld/Common/ErrorHandler.h"
17#include "llvm/ADT/SmallVector.h"
18#include "llvm/ADT/StringRef.h"
19#include "llvm/BinaryFormat/MachO.h"
20#include "llvm/Support/Endian.h"
21#include "llvm/Support/MathExtras.h"
22
23using namespace llvm::MachO;
24using namespace llvm::support::endian;
25using namespace lld;
26using namespace lld::macho;
27
28namespace {
29
30struct ARM64_32 : ARM64Common {
31  ARM64_32();
32  void writeStub(uint8_t *buf, const Symbol &, uint64_t) const override;
33  void writeStubHelperHeader(uint8_t *buf) const override;
34  void writeStubHelperEntry(uint8_t *buf, const Symbol &,
35                            uint64_t entryAddr) const override;
36  void writeObjCMsgSendStub(uint8_t *buf, Symbol *sym, uint64_t stubsAddr,
37                            uint64_t &stubOffset, uint64_t selrefsVA,
38                            uint64_t selectorIndex,
39                            Symbol *objcMsgSend) const override;
40};
41
42} // namespace
43
44// These are very similar to ARM64's relocation attributes, except that we don't
45// have the BYTE8 flag set.
46static constexpr std::array<RelocAttrs, 11> relocAttrsArray{{
47#define B(x) RelocAttrBits::x
48    {"UNSIGNED", B(UNSIGNED) | B(ABSOLUTE) | B(EXTERN) | B(LOCAL) | B(BYTE4)},
49    {"SUBTRACTOR", B(SUBTRAHEND) | B(EXTERN) | B(BYTE4)},
50    {"BRANCH26", B(PCREL) | B(EXTERN) | B(BRANCH) | B(BYTE4)},
51    {"PAGE21", B(PCREL) | B(EXTERN) | B(BYTE4)},
52    {"PAGEOFF12", B(ABSOLUTE) | B(EXTERN) | B(BYTE4)},
53    {"GOT_LOAD_PAGE21", B(PCREL) | B(EXTERN) | B(GOT) | B(BYTE4)},
54    {"GOT_LOAD_PAGEOFF12",
55     B(ABSOLUTE) | B(EXTERN) | B(GOT) | B(LOAD) | B(BYTE4)},
56    {"POINTER_TO_GOT", B(PCREL) | B(EXTERN) | B(GOT) | B(POINTER) | B(BYTE4)},
57    {"TLVP_LOAD_PAGE21", B(PCREL) | B(EXTERN) | B(TLV) | B(BYTE4)},
58    {"TLVP_LOAD_PAGEOFF12",
59     B(ABSOLUTE) | B(EXTERN) | B(TLV) | B(LOAD) | B(BYTE4)},
60    {"ADDEND", B(ADDEND)},
61#undef B
62}};
63
64// The stub code is fairly similar to ARM64's, except that we load pointers into
65// 32-bit 'w' registers, instead of the 64-bit 'x' ones.
66
67static constexpr uint32_t stubCode[] = {
68    0x90000010, // 00: adrp  x16, __la_symbol_ptr@page
69    0xb9400210, // 04: ldr   w16, [x16, __la_symbol_ptr@pageoff]
70    0xd61f0200, // 08: br    x16
71};
72
73void ARM64_32::writeStub(uint8_t *buf8, const Symbol &sym,
74                         uint64_t pointerVA) const {
75  ::writeStub(buf8, stubCode, sym, pointerVA);
76}
77
78static constexpr uint32_t stubHelperHeaderCode[] = {
79    0x90000011, // 00: adrp  x17, _dyld_private@page
80    0x91000231, // 04: add   x17, x17, _dyld_private@pageoff
81    0xa9bf47f0, // 08: stp   x16/x17, [sp, #-16]!
82    0x90000010, // 0c: adrp  x16, dyld_stub_binder@page
83    0xb9400210, // 10: ldr   w16, [x16, dyld_stub_binder@pageoff]
84    0xd61f0200, // 14: br    x16
85};
86
87void ARM64_32::writeStubHelperHeader(uint8_t *buf8) const {
88  ::writeStubHelperHeader<ILP32>(buf8, stubHelperHeaderCode);
89}
90
91static constexpr uint32_t stubHelperEntryCode[] = {
92    0x18000050, // 00: ldr  w16, l0
93    0x14000000, // 04: b    stubHelperHeader
94    0x00000000, // 08: l0: .long 0
95};
96
97void ARM64_32::writeStubHelperEntry(uint8_t *buf8, const Symbol &sym,
98                                    uint64_t entryVA) const {
99  ::writeStubHelperEntry(buf8, stubHelperEntryCode, sym, entryVA);
100}
101
102void ARM64_32::writeObjCMsgSendStub(uint8_t *buf, Symbol *sym,
103                                    uint64_t stubsAddr, uint64_t &stubOffset,
104                                    uint64_t selrefsVA, uint64_t selectorIndex,
105                                    Symbol *objcMsgSend) const {
106  fatal("TODO: implement this");
107}
108
109ARM64_32::ARM64_32() : ARM64Common(ILP32()) {
110  cpuType = CPU_TYPE_ARM64_32;
111  cpuSubtype = CPU_SUBTYPE_ARM64_V8;
112
113  modeDwarfEncoding = 0x04000000;              // UNWIND_ARM_MODE_DWARF
114  subtractorRelocType = GENERIC_RELOC_INVALID; // FIXME
115  unsignedRelocType = GENERIC_RELOC_INVALID;   // FIXME
116
117  stubSize = sizeof(stubCode);
118  stubHelperHeaderSize = sizeof(stubHelperHeaderCode);
119  stubHelperEntrySize = sizeof(stubHelperEntryCode);
120
121  relocAttrs = {relocAttrsArray.data(), relocAttrsArray.size()};
122}
123
124TargetInfo *macho::createARM64_32TargetInfo() {
125  static ARM64_32 t;
126  return &t;
127}
128