1 //===- lib/MC/MCXCOFFStreamer.cpp - XCOFF Object Output -------------------===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 // 9 // This file assembles .s files and emits XCOFF .o object files. 10 // 11 //===----------------------------------------------------------------------===// 12 13 #include "llvm/MC/MCXCOFFStreamer.h" 14 #include "llvm/BinaryFormat/XCOFF.h" 15 #include "llvm/MC/MCAsmBackend.h" 16 #include "llvm/MC/MCAssembler.h" 17 #include "llvm/MC/MCCodeEmitter.h" 18 #include "llvm/MC/MCDirectives.h" 19 #include "llvm/MC/MCObjectWriter.h" 20 #include "llvm/MC/MCSectionXCOFF.h" 21 #include "llvm/MC/MCSymbolXCOFF.h" 22 #include "llvm/MC/TargetRegistry.h" 23 #include "llvm/Support/Casting.h" 24 25 using namespace llvm; 26 27 MCXCOFFStreamer::MCXCOFFStreamer(MCContext &Context, 28 std::unique_ptr<MCAsmBackend> MAB, 29 std::unique_ptr<MCObjectWriter> OW, 30 std::unique_ptr<MCCodeEmitter> Emitter) 31 : MCObjectStreamer(Context, std::move(MAB), std::move(OW), 32 std::move(Emitter)) {} 33 34 bool MCXCOFFStreamer::emitSymbolAttribute(MCSymbol *Sym, 35 MCSymbolAttr Attribute) { 36 auto *Symbol = cast<MCSymbolXCOFF>(Sym); 37 getAssembler().registerSymbol(*Symbol); 38 39 switch (Attribute) { 40 // XCOFF doesn't support the cold feature. 41 case MCSA_Cold: 42 return false; 43 44 case MCSA_Global: 45 case MCSA_Extern: 46 Symbol->setStorageClass(XCOFF::C_EXT); 47 Symbol->setExternal(true); 48 break; 49 case MCSA_LGlobal: 50 Symbol->setStorageClass(XCOFF::C_HIDEXT); 51 Symbol->setExternal(true); 52 break; 53 case llvm::MCSA_Weak: 54 Symbol->setStorageClass(XCOFF::C_WEAKEXT); 55 Symbol->setExternal(true); 56 break; 57 case llvm::MCSA_Hidden: 58 Symbol->setVisibilityType(XCOFF::SYM_V_HIDDEN); 59 break; 60 case llvm::MCSA_Protected: 61 Symbol->setVisibilityType(XCOFF::SYM_V_PROTECTED); 62 break; 63 case llvm::MCSA_Exported: 64 Symbol->setVisibilityType(XCOFF::SYM_V_EXPORTED); 65 break; 66 default: 67 report_fatal_error("Not implemented yet."); 68 } 69 return true; 70 } 71 72 void MCXCOFFStreamer::emitXCOFFSymbolLinkageWithVisibility( 73 MCSymbol *Symbol, MCSymbolAttr Linkage, MCSymbolAttr Visibility) { 74 75 emitSymbolAttribute(Symbol, Linkage); 76 77 // When the caller passes `MCSA_Invalid` for the visibility, do not emit one. 78 if (Visibility == MCSA_Invalid) 79 return; 80 81 emitSymbolAttribute(Symbol, Visibility); 82 } 83 84 void MCXCOFFStreamer::emitXCOFFExceptDirective(const MCSymbol *Symbol, 85 const MCSymbol *Trap, 86 unsigned Lang, unsigned Reason, 87 unsigned FunctionSize, 88 bool hasDebug) { 89 getAssembler().getWriter().addExceptionEntry(Symbol, Trap, Lang, Reason, 90 FunctionSize, hasDebug); 91 } 92 93 void MCXCOFFStreamer::emitCommonSymbol(MCSymbol *Symbol, uint64_t Size, 94 Align ByteAlignment) { 95 getAssembler().registerSymbol(*Symbol); 96 Symbol->setExternal(cast<MCSymbolXCOFF>(Symbol)->getStorageClass() != 97 XCOFF::C_HIDEXT); 98 Symbol->setCommon(Size, ByteAlignment); 99 100 // Default csect align is 4, but common symbols have explicit alignment values 101 // and we should honor it. 102 cast<MCSymbolXCOFF>(Symbol)->getRepresentedCsect()->setAlignment( 103 ByteAlignment); 104 105 // Emit the alignment and storage for the variable to the section. 106 emitValueToAlignment(ByteAlignment); 107 emitZeros(Size); 108 } 109 110 void MCXCOFFStreamer::emitZerofill(MCSection *Section, MCSymbol *Symbol, 111 uint64_t Size, Align ByteAlignment, 112 SMLoc Loc) { 113 report_fatal_error("Zero fill not implemented for XCOFF."); 114 } 115 116 void MCXCOFFStreamer::emitInstToData(const MCInst &Inst, 117 const MCSubtargetInfo &STI) { 118 MCAssembler &Assembler = getAssembler(); 119 SmallVector<MCFixup, 4> Fixups; 120 SmallString<256> Code; 121 raw_svector_ostream VecOS(Code); 122 Assembler.getEmitter().encodeInstruction(Inst, VecOS, Fixups, STI); 123 124 // Add the fixups and data. 125 MCDataFragment *DF = getOrCreateDataFragment(&STI); 126 const size_t ContentsSize = DF->getContents().size(); 127 auto &DataFragmentFixups = DF->getFixups(); 128 for (auto &Fixup : Fixups) { 129 Fixup.setOffset(Fixup.getOffset() + ContentsSize); 130 DataFragmentFixups.push_back(Fixup); 131 } 132 133 DF->setHasInstructions(STI); 134 DF->getContents().append(Code.begin(), Code.end()); 135 } 136 137 MCStreamer *llvm::createXCOFFStreamer(MCContext &Context, 138 std::unique_ptr<MCAsmBackend> &&MAB, 139 std::unique_ptr<MCObjectWriter> &&OW, 140 std::unique_ptr<MCCodeEmitter> &&CE, 141 bool RelaxAll) { 142 MCXCOFFStreamer *S = new MCXCOFFStreamer(Context, std::move(MAB), 143 std::move(OW), std::move(CE)); 144 if (RelaxAll) 145 S->getAssembler().setRelaxAll(true); 146 return S; 147 } 148 149 void MCXCOFFStreamer::emitXCOFFLocalCommonSymbol(MCSymbol *LabelSym, 150 uint64_t Size, 151 MCSymbol *CsectSym, 152 Align Alignment) { 153 emitCommonSymbol(CsectSym, Size, Alignment); 154 } 155