1 //===-- XCoreTargetObjectFile.cpp - XCore object files --------------------===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 10 #include "XCoreTargetObjectFile.h" 11 #include "XCoreSubtarget.h" 12 #include "llvm/BinaryFormat/ELF.h" 13 #include "llvm/IR/DataLayout.h" 14 #include "llvm/MC/MCContext.h" 15 #include "llvm/MC/MCSectionELF.h" 16 #include "llvm/Target/TargetMachine.h" 17 18 using namespace llvm; 19 20 21 void XCoreTargetObjectFile::Initialize(MCContext &Ctx, const TargetMachine &TM){ 22 TargetLoweringObjectFileELF::Initialize(Ctx, TM); 23 24 BSSSection = Ctx.getELFSection(".dp.bss", ELF::SHT_NOBITS, 25 ELF::SHF_ALLOC | ELF::SHF_WRITE | 26 ELF::XCORE_SHF_DP_SECTION); 27 BSSSectionLarge = Ctx.getELFSection(".dp.bss.large", ELF::SHT_NOBITS, 28 ELF::SHF_ALLOC | ELF::SHF_WRITE | 29 ELF::XCORE_SHF_DP_SECTION); 30 DataSection = Ctx.getELFSection(".dp.data", ELF::SHT_PROGBITS, 31 ELF::SHF_ALLOC | ELF::SHF_WRITE | 32 ELF::XCORE_SHF_DP_SECTION); 33 DataSectionLarge = Ctx.getELFSection(".dp.data.large", ELF::SHT_PROGBITS, 34 ELF::SHF_ALLOC | ELF::SHF_WRITE | 35 ELF::XCORE_SHF_DP_SECTION); 36 DataRelROSection = Ctx.getELFSection(".dp.rodata", ELF::SHT_PROGBITS, 37 ELF::SHF_ALLOC | ELF::SHF_WRITE | 38 ELF::XCORE_SHF_DP_SECTION); 39 DataRelROSectionLarge = Ctx.getELFSection( 40 ".dp.rodata.large", ELF::SHT_PROGBITS, 41 ELF::SHF_ALLOC | ELF::SHF_WRITE | ELF::XCORE_SHF_DP_SECTION); 42 ReadOnlySection = 43 Ctx.getELFSection(".cp.rodata", ELF::SHT_PROGBITS, 44 ELF::SHF_ALLOC | ELF::XCORE_SHF_CP_SECTION); 45 ReadOnlySectionLarge = 46 Ctx.getELFSection(".cp.rodata.large", ELF::SHT_PROGBITS, 47 ELF::SHF_ALLOC | ELF::XCORE_SHF_CP_SECTION); 48 MergeableConst4Section = Ctx.getELFSection( 49 ".cp.rodata.cst4", ELF::SHT_PROGBITS, 50 ELF::SHF_ALLOC | ELF::SHF_MERGE | ELF::XCORE_SHF_CP_SECTION, 4, ""); 51 MergeableConst8Section = Ctx.getELFSection( 52 ".cp.rodata.cst8", ELF::SHT_PROGBITS, 53 ELF::SHF_ALLOC | ELF::SHF_MERGE | ELF::XCORE_SHF_CP_SECTION, 8, ""); 54 MergeableConst16Section = Ctx.getELFSection( 55 ".cp.rodata.cst16", ELF::SHT_PROGBITS, 56 ELF::SHF_ALLOC | ELF::SHF_MERGE | ELF::XCORE_SHF_CP_SECTION, 16, ""); 57 CStringSection = 58 Ctx.getELFSection(".cp.rodata.string", ELF::SHT_PROGBITS, 59 ELF::SHF_ALLOC | ELF::SHF_MERGE | ELF::SHF_STRINGS | 60 ELF::XCORE_SHF_CP_SECTION); 61 // TextSection - see MObjectFileInfo.cpp 62 // StaticCtorSection - see MObjectFileInfo.cpp 63 // StaticDtorSection - see MObjectFileInfo.cpp 64 } 65 66 static unsigned getXCoreSectionType(SectionKind K) { 67 if (K.isBSS()) 68 return ELF::SHT_NOBITS; 69 return ELF::SHT_PROGBITS; 70 } 71 72 static unsigned getXCoreSectionFlags(SectionKind K, bool IsCPRel) { 73 unsigned Flags = 0; 74 75 if (!K.isMetadata()) 76 Flags |= ELF::SHF_ALLOC; 77 78 if (K.isText()) 79 Flags |= ELF::SHF_EXECINSTR; 80 else if (IsCPRel) 81 Flags |= ELF::XCORE_SHF_CP_SECTION; 82 else 83 Flags |= ELF::XCORE_SHF_DP_SECTION; 84 85 if (K.isWriteable()) 86 Flags |= ELF::SHF_WRITE; 87 88 if (K.isMergeableCString() || K.isMergeableConst4() || 89 K.isMergeableConst8() || K.isMergeableConst16()) 90 Flags |= ELF::SHF_MERGE; 91 92 if (K.isMergeableCString()) 93 Flags |= ELF::SHF_STRINGS; 94 95 return Flags; 96 } 97 98 MCSection *XCoreTargetObjectFile::getExplicitSectionGlobal( 99 const GlobalObject *GO, SectionKind Kind, const TargetMachine &TM) const { 100 StringRef SectionName = GO->getSection(); 101 // Infer section flags from the section name if we can. 102 bool IsCPRel = SectionName.startswith(".cp."); 103 if (IsCPRel && !Kind.isReadOnly()) 104 report_fatal_error("Using .cp. section for writeable object."); 105 return getContext().getELFSection(SectionName, getXCoreSectionType(Kind), 106 getXCoreSectionFlags(Kind, IsCPRel)); 107 } 108 109 MCSection *XCoreTargetObjectFile::SelectSectionForGlobal( 110 const GlobalObject *GO, SectionKind Kind, const TargetMachine &TM) const { 111 112 bool UseCPRel = GO->hasLocalLinkage(); 113 114 if (Kind.isText()) return TextSection; 115 if (UseCPRel) { 116 if (Kind.isMergeable1ByteCString()) return CStringSection; 117 if (Kind.isMergeableConst4()) return MergeableConst4Section; 118 if (Kind.isMergeableConst8()) return MergeableConst8Section; 119 if (Kind.isMergeableConst16()) return MergeableConst16Section; 120 } 121 Type *ObjType = GO->getValueType(); 122 auto &DL = GO->getParent()->getDataLayout(); 123 if (TM.getCodeModel() == CodeModel::Small || !ObjType->isSized() || 124 DL.getTypeAllocSize(ObjType) < CodeModelLargeSize) { 125 if (Kind.isReadOnly()) return UseCPRel? ReadOnlySection 126 : DataRelROSection; 127 if (Kind.isBSS() || Kind.isCommon())return BSSSection; 128 if (Kind.isData()) 129 return DataSection; 130 if (Kind.isReadOnlyWithRel()) return DataRelROSection; 131 } else { 132 if (Kind.isReadOnly()) return UseCPRel? ReadOnlySectionLarge 133 : DataRelROSectionLarge; 134 if (Kind.isBSS() || Kind.isCommon())return BSSSectionLarge; 135 if (Kind.isData()) 136 return DataSectionLarge; 137 if (Kind.isReadOnlyWithRel()) return DataRelROSectionLarge; 138 } 139 140 assert((Kind.isThreadLocal() || Kind.isCommon()) && "Unknown section kind"); 141 report_fatal_error("Target does not support TLS or Common sections"); 142 } 143 144 MCSection *XCoreTargetObjectFile::getSectionForConstant(const DataLayout &DL, 145 SectionKind Kind, 146 const Constant *C, 147 unsigned &Align) const { 148 if (Kind.isMergeableConst4()) return MergeableConst4Section; 149 if (Kind.isMergeableConst8()) return MergeableConst8Section; 150 if (Kind.isMergeableConst16()) return MergeableConst16Section; 151 assert((Kind.isReadOnly() || Kind.isReadOnlyWithRel()) && 152 "Unknown section kind"); 153 // We assume the size of the object is never greater than CodeModelLargeSize. 154 // To handle CodeModelLargeSize changes to AsmPrinter would be required. 155 return ReadOnlySection; 156 } 157
