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