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 selrefVA,
38 Symbol *objcMsgSend) const override;
39};
40
41} // namespace
42
43// These are very similar to ARM64's relocation attributes, except that we don't
44// have the BYTE8 flag set.
45static constexpr std::array<RelocAttrs, 11> relocAttrsArray{._M_elems: {
46#define B(x) RelocAttrBits::x
47 {.name: "UNSIGNED", B(UNSIGNED) | B(ABSOLUTE) | B(EXTERN) | B(LOCAL) | B(BYTE4)},
48 {.name: "SUBTRACTOR", B(SUBTRAHEND) | B(EXTERN) | B(BYTE4)},
49 {.name: "BRANCH26", B(PCREL) | B(EXTERN) | B(BRANCH) | B(BYTE4)},
50 {.name: "PAGE21", B(PCREL) | B(EXTERN) | B(BYTE4)},
51 {.name: "PAGEOFF12", B(ABSOLUTE) | B(EXTERN) | B(BYTE4)},
52 {.name: "GOT_LOAD_PAGE21", B(PCREL) | B(EXTERN) | B(GOT) | B(BYTE4)},
53 {.name: "GOT_LOAD_PAGEOFF12",
54 B(ABSOLUTE) | B(EXTERN) | B(GOT) | B(LOAD) | B(BYTE4)},
55 {.name: "POINTER_TO_GOT", B(PCREL) | B(EXTERN) | B(GOT) | B(POINTER) | B(BYTE4)},
56 {.name: "TLVP_LOAD_PAGE21", B(PCREL) | B(EXTERN) | B(TLV) | B(BYTE4)},
57 {.name: "TLVP_LOAD_PAGEOFF12",
58 B(ABSOLUTE) | B(EXTERN) | B(TLV) | B(LOAD) | B(BYTE4)},
59 {.name: "ADDEND", B(ADDEND)},
60#undef B
61}};
62
63// The stub code is fairly similar to ARM64's, except that we load pointers into
64// 32-bit 'w' registers, instead of the 64-bit 'x' ones.
65
66static constexpr uint32_t stubCode[] = {
67 0x90000010, // 00: adrp x16, __la_symbol_ptr@page
68 0xb9400210, // 04: ldr w16, [x16, __la_symbol_ptr@pageoff]
69 0xd61f0200, // 08: br x16
70};
71
72void ARM64_32::writeStub(uint8_t *buf8, const Symbol &sym,
73 uint64_t pointerVA) const {
74 ::writeStub(buf8, stubCode, sym, pointerVA);
75}
76
77static constexpr uint32_t stubHelperHeaderCode[] = {
78 0x90000011, // 00: adrp x17, _dyld_private@page
79 0x91000231, // 04: add x17, x17, _dyld_private@pageoff
80 0xa9bf47f0, // 08: stp x16/x17, [sp, #-16]!
81 0x90000010, // 0c: adrp x16, dyld_stub_binder@page
82 0xb9400210, // 10: ldr w16, [x16, dyld_stub_binder@pageoff]
83 0xd61f0200, // 14: br x16
84};
85
86void ARM64_32::writeStubHelperHeader(uint8_t *buf8) const {
87 ::writeStubHelperHeader<ILP32>(buf8, stubHelperHeaderCode);
88}
89
90static constexpr uint32_t stubHelperEntryCode[] = {
91 0x18000050, // 00: ldr w16, l0
92 0x14000000, // 04: b stubHelperHeader
93 0x00000000, // 08: l0: .long 0
94};
95
96void ARM64_32::writeStubHelperEntry(uint8_t *buf8, const Symbol &sym,
97 uint64_t entryVA) const {
98 ::writeStubHelperEntry(buf8, stubHelperEntryCode, sym, entryVA);
99}
100
101void ARM64_32::writeObjCMsgSendStub(uint8_t *buf, Symbol *sym,
102 uint64_t stubsAddr, uint64_t &stubOffset,
103 uint64_t selrefVA,
104 Symbol *objcMsgSend) const {
105 fatal(msg: "TODO: implement this");
106}
107
108ARM64_32::ARM64_32() : ARM64Common(ILP32()) {
109 cpuType = CPU_TYPE_ARM64_32;
110 cpuSubtype = CPU_SUBTYPE_ARM64_V8;
111
112 modeDwarfEncoding = 0x04000000; // UNWIND_ARM_MODE_DWARF
113 subtractorRelocType = GENERIC_RELOC_INVALID; // FIXME
114 unsignedRelocType = GENERIC_RELOC_INVALID; // FIXME
115
116 stubSize = sizeof(stubCode);
117 stubHelperHeaderSize = sizeof(stubHelperHeaderCode);
118 stubHelperEntrySize = sizeof(stubHelperEntryCode);
119
120 relocAttrs = {relocAttrsArray.data(), relocAttrsArray.size()};
121}
122
123TargetInfo *macho::createARM64_32TargetInfo() {
124 static ARM64_32 t;
125 return &t;
126}
127

source code of lld/MachO/Arch/ARM64_32.cpp