PPCMachObjectWriter.cpp revision f69a29b23a116a3520f185054290c445abf9aa62
1d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang//===-- PPCMachObjectWriter.cpp - PPC Mach-O Writer -----------------------===// 2d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang// 3d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang// The LLVM Compiler Infrastructure 4d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang// 5d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang// This file is distributed under the University of Illinois Open Source 6d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang// License. See LICENSE.TXT for details. 7d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang// 8d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang//===----------------------------------------------------------------------===// 9d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang 10d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang#include "MCTargetDesc/PPCMCTargetDesc.h" 11d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang#include "MCTargetDesc/PPCFixupKinds.h" 12d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang#include "llvm/ADT/Twine.h" 13d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang#include "llvm/MC/MCAsmLayout.h" 14d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang#include "llvm/MC/MCAssembler.h" 15d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang#include "llvm/MC/MCContext.h" 16d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang#include "llvm/MC/MCMachObjectWriter.h" 17d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang#include "llvm/MC/MCSectionMachO.h" 18d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang#include "llvm/MC/MCValue.h" 19f69a29b23a116a3520f185054290c445abf9aa62Charles Davis#include "llvm/Object/MachOFormat.h" 20d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang#include "llvm/Support/ErrorHandling.h" 21d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang#include "llvm/Support/Format.h" 22d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang 23d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fangusing namespace llvm; 24f69a29b23a116a3520f185054290c445abf9aa62Charles Davisusing namespace llvm::object; 25d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang 26d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fangnamespace { 27d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fangclass PPCMachObjectWriter : public MCMachObjectTargetWriter { 28d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang bool RecordScatteredRelocation(MachObjectWriter *Writer, 29d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang const MCAssembler &Asm, 30d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang const MCAsmLayout &Layout, 31d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang const MCFragment *Fragment, 32d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang const MCFixup &Fixup, MCValue Target, 33d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang unsigned Log2Size, uint64_t &FixedValue); 34d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang 35d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang void RecordPPCRelocation(MachObjectWriter *Writer, const MCAssembler &Asm, 36d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang const MCAsmLayout &Layout, 37d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang const MCFragment *Fragment, const MCFixup &Fixup, 38d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang MCValue Target, uint64_t &FixedValue); 39d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang 40d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fangpublic: 41d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang PPCMachObjectWriter(bool Is64Bit, uint32_t CPUType, uint32_t CPUSubtype) 42d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang : MCMachObjectTargetWriter(Is64Bit, CPUType, CPUSubtype, 43d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang /*UseAggressiveSymbolFolding=*/Is64Bit) {} 44d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang 45d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang void RecordRelocation(MachObjectWriter *Writer, const MCAssembler &Asm, 46d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang const MCAsmLayout &Layout, const MCFragment *Fragment, 47d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang const MCFixup &Fixup, MCValue Target, 48d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang uint64_t &FixedValue) { 49d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang if (Writer->is64Bit()) { 50d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang report_fatal_error("Relocation emission for MachO/PPC64 unimplemented."); 51d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang } else 52d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang RecordPPCRelocation(Writer, Asm, Layout, Fragment, Fixup, Target, 53d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang FixedValue); 54d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang } 55d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang}; 56d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang} 57d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang 58d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang/// computes the log2 of the size of the relocation, 59d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang/// used for relocation_info::r_length. 60d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fangstatic unsigned getFixupKindLog2Size(unsigned Kind) { 61d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang switch (Kind) { 62d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang default: 63d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang report_fatal_error("log2size(FixupKind): Unhandled fixup kind!"); 64d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang case FK_PCRel_1: 65d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang case FK_Data_1: 66d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang return 0; 67d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang case FK_PCRel_2: 68d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang case FK_Data_2: 69d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang return 1; 70d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang case FK_PCRel_4: 71d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang case PPC::fixup_ppc_brcond14: 72d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang case PPC::fixup_ppc_half16: 73d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang case PPC::fixup_ppc_br24: 74d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang case FK_Data_4: 75d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang return 2; 76d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang case FK_PCRel_8: 77d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang case FK_Data_8: 78d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang return 3; 79d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang } 80d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang return 0; 81d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang} 82d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang 83d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang/// Translates generic PPC fixup kind to Mach-O/PPC relocation type enum. 84d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang/// Outline based on PPCELFObjectWriter::getRelocTypeInner(). 85d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fangstatic unsigned getRelocType(const MCValue &Target, 86d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang const MCFixupKind FixupKind, // from 87d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang // Fixup.getKind() 88d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang const bool IsPCRel) { 89d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang const MCSymbolRefExpr::VariantKind Modifier = 90d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang Target.isAbsolute() ? MCSymbolRefExpr::VK_None 91d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang : Target.getSymA()->getKind(); 92d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang // determine the type of the relocation 93f69a29b23a116a3520f185054290c445abf9aa62Charles Davis unsigned Type = macho::RIT_Vanilla; 94d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang if (IsPCRel) { // relative to PC 95d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang switch ((unsigned)FixupKind) { 96d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang default: 97d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang report_fatal_error("Unimplemented fixup kind (relative)"); 98d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang case PPC::fixup_ppc_br24: 99f69a29b23a116a3520f185054290c445abf9aa62Charles Davis Type = macho::RIT_PPC_BR24; // R_PPC_REL24 100d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang break; 101d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang case PPC::fixup_ppc_brcond14: 102f69a29b23a116a3520f185054290c445abf9aa62Charles Davis Type = macho::RIT_PPC_BR14; 103d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang break; 104d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang case PPC::fixup_ppc_half16: 105d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang switch (Modifier) { 106d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang default: 107d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang llvm_unreachable("Unsupported modifier for half16 fixup"); 108d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang case MCSymbolRefExpr::VK_PPC_HA: 109f69a29b23a116a3520f185054290c445abf9aa62Charles Davis Type = macho::RIT_PPC_HA16; 110d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang break; 111d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang case MCSymbolRefExpr::VK_PPC_LO: 112f69a29b23a116a3520f185054290c445abf9aa62Charles Davis Type = macho::RIT_PPC_LO16; 113d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang break; 114d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang case MCSymbolRefExpr::VK_PPC_HI: 115f69a29b23a116a3520f185054290c445abf9aa62Charles Davis Type = macho::RIT_PPC_HI16; 116d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang break; 117d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang } 118d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang break; 119d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang } 120d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang } else { 121d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang switch ((unsigned)FixupKind) { 122d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang default: 123d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang report_fatal_error("Unimplemented fixup kind (absolute)!"); 124d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang case PPC::fixup_ppc_half16: 125d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang switch (Modifier) { 126d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang default: 127d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang llvm_unreachable("Unsupported modifier for half16 fixup"); 128d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang case MCSymbolRefExpr::VK_PPC_HA: 129f69a29b23a116a3520f185054290c445abf9aa62Charles Davis Type = macho::RIT_PPC_HA16_SECTDIFF; 130d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang break; 131d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang case MCSymbolRefExpr::VK_PPC_LO: 132f69a29b23a116a3520f185054290c445abf9aa62Charles Davis Type = macho::RIT_PPC_LO16_SECTDIFF; 133d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang break; 134d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang case MCSymbolRefExpr::VK_PPC_HI: 135f69a29b23a116a3520f185054290c445abf9aa62Charles Davis Type = macho::RIT_PPC_HI16_SECTDIFF; 136d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang break; 137d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang } 138d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang break; 139d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang case FK_Data_4: 140d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang break; 141d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang case FK_Data_2: 142d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang break; 143d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang } 144d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang } 145d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang return Type; 146d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang} 147d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang 148f69a29b23a116a3520f185054290c445abf9aa62Charles Davisstatic void makeRelocationInfo(macho::RelocationEntry &MRE, 149d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang const uint32_t FixupOffset, const uint32_t Index, 150d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang const unsigned IsPCRel, const unsigned Log2Size, 151d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang const unsigned IsExtern, const unsigned Type) { 152f69a29b23a116a3520f185054290c445abf9aa62Charles Davis MRE.Word0 = FixupOffset; 153d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang // The bitfield offsets that work (as determined by trial-and-error) 154d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang // are different than what is documented in the mach-o manuals. 155f69a29b23a116a3520f185054290c445abf9aa62Charles Davis // Is this an endianness issue w/ PPC? 156f69a29b23a116a3520f185054290c445abf9aa62Charles Davis MRE.Word1 = ((Index << 8) | // was << 0 157f69a29b23a116a3520f185054290c445abf9aa62Charles Davis (IsPCRel << 7) | // was << 24 158f69a29b23a116a3520f185054290c445abf9aa62Charles Davis (Log2Size << 5) | // was << 25 159f69a29b23a116a3520f185054290c445abf9aa62Charles Davis (IsExtern << 4) | // was << 27 160f69a29b23a116a3520f185054290c445abf9aa62Charles Davis (Type << 0)); // was << 28 161d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang} 162d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang 163d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fangstatic void 164f69a29b23a116a3520f185054290c445abf9aa62Charles DavismakeScatteredRelocationInfo(macho::RelocationEntry &MRE, const uint32_t Addr, 165f69a29b23a116a3520f185054290c445abf9aa62Charles Davis const unsigned Type, const unsigned Log2Size, 166f69a29b23a116a3520f185054290c445abf9aa62Charles Davis const unsigned IsPCRel, const uint32_t Value2) { 167f69a29b23a116a3520f185054290c445abf9aa62Charles Davis // For notes on bitfield positions and endianness, see: 168f69a29b23a116a3520f185054290c445abf9aa62Charles Davis // https://developer.apple.com/library/mac/documentation/developertools/conceptual/MachORuntime/Reference/reference.html#//apple_ref/doc/uid/20001298-scattered_relocation_entry 169f69a29b23a116a3520f185054290c445abf9aa62Charles Davis MRE.Word0 = ((Addr << 0) | (Type << 24) | (Log2Size << 28) | (IsPCRel << 30) | 170f69a29b23a116a3520f185054290c445abf9aa62Charles Davis macho::RF_Scattered); 171f69a29b23a116a3520f185054290c445abf9aa62Charles Davis MRE.Word1 = Value2; 172d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang} 173d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang 174d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang/// Compute fixup offset (address). 175d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fangstatic uint32_t getFixupOffset(const MCAsmLayout &Layout, 176d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang const MCFragment *Fragment, 177d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang const MCFixup &Fixup) { 178d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang uint32_t FixupOffset = Layout.getFragmentOffset(Fragment) + Fixup.getOffset(); 179d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang // On Mach-O, ppc_fixup_half16 relocations must refer to the 180d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang // start of the instruction, not the second halfword, as ELF does 181d76adee1b214fe1f5a26b8ffaec3e461beda6c88David Fang if (unsigned(Fixup.getKind()) == PPC::fixup_ppc_half16) 182d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang FixupOffset &= ~uint32_t(3); 183d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang return FixupOffset; 184d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang} 185d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang 186d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang/// \return false if falling back to using non-scattered relocation, 187d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang/// otherwise true for normal scattered relocation. 188d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang/// based on X86MachObjectWriter::RecordScatteredRelocation 189d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang/// and ARMMachObjectWriter::RecordScatteredRelocation 190d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fangbool PPCMachObjectWriter::RecordScatteredRelocation( 191d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang MachObjectWriter *Writer, const MCAssembler &Asm, const MCAsmLayout &Layout, 192d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang const MCFragment *Fragment, const MCFixup &Fixup, MCValue Target, 193d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang unsigned Log2Size, uint64_t &FixedValue) { 194d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang // caller already computes these, can we just pass and reuse? 195d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang const uint32_t FixupOffset = getFixupOffset(Layout, Fragment, Fixup); 196d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang const MCFixupKind FK = Fixup.getKind(); 197d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang const unsigned IsPCRel = Writer->isFixupKindPCRel(Asm, FK); 198d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang const unsigned Type = getRelocType(Target, FK, IsPCRel); 199d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang 200d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang // Is this a local or SECTDIFF relocation entry? 201d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang // SECTDIFF relocation entries have symbol subtractions, 202d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang // and require two entries, the first for the add-symbol value, 203d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang // the second for the subtract-symbol value. 204d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang 205d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang // See <reloc.h>. 206d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang const MCSymbol *A = &Target.getSymA()->getSymbol(); 207d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang MCSymbolData *A_SD = &Asm.getSymbolData(*A); 208d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang 209d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang if (!A_SD->getFragment()) 210d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang report_fatal_error("symbol '" + A->getName() + 211d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang "' can not be undefined in a subtraction expression"); 212d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang 213d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang uint32_t Value = Writer->getSymbolAddress(A_SD, Layout); 214d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang uint64_t SecAddr = 215d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang Writer->getSectionAddress(A_SD->getFragment()->getParent()); 216d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang FixedValue += SecAddr; 217d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang uint32_t Value2 = 0; 218d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang 219d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang if (const MCSymbolRefExpr *B = Target.getSymB()) { 220d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang MCSymbolData *B_SD = &Asm.getSymbolData(B->getSymbol()); 221d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang 222d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang if (!B_SD->getFragment()) 223d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang report_fatal_error("symbol '" + B->getSymbol().getName() + 224d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang "' can not be undefined in a subtraction expression"); 225d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang 226f69a29b23a116a3520f185054290c445abf9aa62Charles Davis // FIXME: is Type correct? see include/llvm/Object/MachOFormat.h 227d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang Value2 = Writer->getSymbolAddress(B_SD, Layout); 228d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang FixedValue -= Writer->getSectionAddress(B_SD->getFragment()->getParent()); 229d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang } 230d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang // FIXME: does FixedValue get used?? 231d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang 232d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang // Relocations are written out in reverse order, so the PAIR comes first. 233f69a29b23a116a3520f185054290c445abf9aa62Charles Davis if (Type == macho::RIT_PPC_SECTDIFF || Type == macho::RIT_PPC_HI16_SECTDIFF || 234f69a29b23a116a3520f185054290c445abf9aa62Charles Davis Type == macho::RIT_PPC_LO16_SECTDIFF || 235f69a29b23a116a3520f185054290c445abf9aa62Charles Davis Type == macho::RIT_PPC_HA16_SECTDIFF || 236f69a29b23a116a3520f185054290c445abf9aa62Charles Davis Type == macho::RIT_PPC_LO14_SECTDIFF || 237f69a29b23a116a3520f185054290c445abf9aa62Charles Davis Type == macho::RIT_PPC_LOCAL_SECTDIFF) { 238d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang // X86 had this piece, but ARM does not 239d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang // If the offset is too large to fit in a scattered relocation, 240d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang // we're hosed. It's an unfortunate limitation of the MachO format. 241d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang if (FixupOffset > 0xffffff) { 242d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang char Buffer[32]; 243d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang format("0x%x", FixupOffset).print(Buffer, sizeof(Buffer)); 244d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang Asm.getContext().FatalError(Fixup.getLoc(), 245d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang Twine("Section too large, can't encode " 246d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang "r_address (") + 247d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang Buffer + ") into 24 bits of scattered " 248d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang "relocation entry."); 249d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang llvm_unreachable("fatal error returned?!"); 250d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang } 251d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang 252d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang // Is this supposed to follow MCTarget/PPCAsmBackend.cpp:adjustFixupValue()? 253d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang // see PPCMCExpr::EvaluateAsRelocatableImpl() 254d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang uint32_t other_half = 0; 255d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang switch (Type) { 256f69a29b23a116a3520f185054290c445abf9aa62Charles Davis case macho::RIT_PPC_LO16_SECTDIFF: 257d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang other_half = (FixedValue >> 16) & 0xffff; 258d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang // applyFixupOffset longer extracts the high part because it now assumes 259d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang // this was already done. 260d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang // It looks like this is not true for the FixedValue needed with Mach-O 261d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang // relocs. 262d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang // So we need to adjust FixedValue again here. 263d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang FixedValue &= 0xffff; 264d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang break; 265f69a29b23a116a3520f185054290c445abf9aa62Charles Davis case macho::RIT_PPC_HA16_SECTDIFF: 266d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang other_half = FixedValue & 0xffff; 267d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang FixedValue = 268d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang ((FixedValue >> 16) + ((FixedValue & 0x8000) ? 1 : 0)) & 0xffff; 269d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang break; 270f69a29b23a116a3520f185054290c445abf9aa62Charles Davis case macho::RIT_PPC_HI16_SECTDIFF: 271d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang other_half = FixedValue & 0xffff; 272d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang FixedValue = (FixedValue >> 16) & 0xffff; 273d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang break; 274d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang default: 275d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang llvm_unreachable("Invalid PPC scattered relocation type."); 276d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang break; 277d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang } 278d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang 279f69a29b23a116a3520f185054290c445abf9aa62Charles Davis macho::RelocationEntry MRE; 280f69a29b23a116a3520f185054290c445abf9aa62Charles Davis makeScatteredRelocationInfo(MRE, other_half, macho::RIT_Pair, Log2Size, 281f69a29b23a116a3520f185054290c445abf9aa62Charles Davis IsPCRel, Value2); 282d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang Writer->addRelocation(Fragment->getParent(), MRE); 283d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang } else { 284d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang // If the offset is more than 24-bits, it won't fit in a scattered 285d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang // relocation offset field, so we fall back to using a non-scattered 286d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang // relocation. This is a bit risky, as if the offset reaches out of 287d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang // the block and the linker is doing scattered loading on this 288d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang // symbol, things can go badly. 289d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang // 290d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang // Required for 'as' compatibility. 291d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang if (FixupOffset > 0xffffff) 292d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang return false; 293d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang } 294f69a29b23a116a3520f185054290c445abf9aa62Charles Davis macho::RelocationEntry MRE; 295d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang makeScatteredRelocationInfo(MRE, FixupOffset, Type, Log2Size, IsPCRel, Value); 296d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang Writer->addRelocation(Fragment->getParent(), MRE); 297d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang return true; 298d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang} 299d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang 300d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang// see PPCELFObjectWriter for a general outline of cases 301d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fangvoid PPCMachObjectWriter::RecordPPCRelocation( 302d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang MachObjectWriter *Writer, const MCAssembler &Asm, const MCAsmLayout &Layout, 303d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang const MCFragment *Fragment, const MCFixup &Fixup, MCValue Target, 304d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang uint64_t &FixedValue) { 305d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang const MCFixupKind FK = Fixup.getKind(); // unsigned 306d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang const unsigned Log2Size = getFixupKindLog2Size(FK); 307d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang const bool IsPCRel = Writer->isFixupKindPCRel(Asm, FK); 308d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang const unsigned RelocType = getRelocType(Target, FK, IsPCRel); 309d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang 310d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang // If this is a difference or a defined symbol plus an offset, then we need a 311d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang // scattered relocation entry. Differences always require scattered 312d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang // relocations. 313d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang if (Target.getSymB() && 314d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang // Q: are branch targets ever scattered? 315f69a29b23a116a3520f185054290c445abf9aa62Charles Davis RelocType != macho::RIT_PPC_BR24 && RelocType != macho::RIT_PPC_BR14) { 316d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang RecordScatteredRelocation(Writer, Asm, Layout, Fragment, Fixup, Target, 317d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang Log2Size, FixedValue); 318d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang return; 319d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang } 320d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang 321d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang // this doesn't seem right for RIT_PPC_BR24 322d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang // Get the symbol data, if any. 323d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang MCSymbolData *SD = 0; 324d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang if (Target.getSymA()) 325d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang SD = &Asm.getSymbolData(Target.getSymA()->getSymbol()); 326d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang 327d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang // See <reloc.h>. 328d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang const uint32_t FixupOffset = getFixupOffset(Layout, Fragment, Fixup); 329d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang unsigned Index = 0; 330d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang unsigned IsExtern = 0; 331d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang unsigned Type = RelocType; 332d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang 333d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang if (Target.isAbsolute()) { // constant 334d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang // SymbolNum of 0 indicates the absolute section. 335d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang // 336d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang // FIXME: Currently, these are never generated (see code below). I cannot 337d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang // find a case where they are actually emitted. 338d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang report_fatal_error("FIXME: relocations to absolute targets " 339d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang "not yet implemented"); 340d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang // the above line stolen from ARM, not sure 341d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang } else { 342d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang // Resolve constant variables. 343d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang if (SD->getSymbol().isVariable()) { 344d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang int64_t Res; 345d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang if (SD->getSymbol().getVariableValue()->EvaluateAsAbsolute( 346d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang Res, Layout, Writer->getSectionAddressMap())) { 347d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang FixedValue = Res; 348d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang return; 349d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang } 350d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang } 351d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang 352d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang // Check whether we need an external or internal relocation. 353d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang if (Writer->doesSymbolRequireExternRelocation(SD)) { 354d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang IsExtern = 1; 355d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang Index = SD->getIndex(); 356d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang // For external relocations, make sure to offset the fixup value to 357d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang // compensate for the addend of the symbol address, if it was 358d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang // undefined. This occurs with weak definitions, for example. 359d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang if (!SD->Symbol->isUndefined()) 360d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang FixedValue -= Layout.getSymbolOffset(SD); 361d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang } else { 362d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang // The index is the section ordinal (1-based). 363d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang const MCSectionData &SymSD = 364d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang Asm.getSectionData(SD->getSymbol().getSection()); 365d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang Index = SymSD.getOrdinal() + 1; 366d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang FixedValue += Writer->getSectionAddress(&SymSD); 367d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang } 368d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang if (IsPCRel) 369d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang FixedValue -= Writer->getSectionAddress(Fragment->getParent()); 370d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang } 371d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang 372f69a29b23a116a3520f185054290c445abf9aa62Charles Davis // struct relocation_info (8 bytes) 373f69a29b23a116a3520f185054290c445abf9aa62Charles Davis macho::RelocationEntry MRE; 374d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang makeRelocationInfo(MRE, FixupOffset, Index, IsPCRel, Log2Size, IsExtern, 375d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang Type); 376d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang Writer->addRelocation(Fragment->getParent(), MRE); 377d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang} 378d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang 379d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid FangMCObjectWriter *llvm::createPPCMachObjectWriter(raw_ostream &OS, bool Is64Bit, 380d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang uint32_t CPUType, 381d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang uint32_t CPUSubtype) { 382d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang return createMachObjectWriter( 383d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang new PPCMachObjectWriter(Is64Bit, CPUType, CPUSubtype), OS, 384d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang /*IsLittleEndian=*/false); 385d4f9d05fde4b2cfd202a5852ec1ec3e960ef53edDavid Fang} 386