//===----------------------------------------------------------------------===//
#define DEBUG_TYPE "elfwriter"
-
#include "ELF.h"
#include "ELFWriter.h"
#include "ELFCodeEmitter.h"
#include "llvm/PassManager.h"
#include "llvm/DerivedTypes.h"
#include "llvm/CodeGen/BinaryObject.h"
-#include "llvm/CodeGen/FileWriters.h"
#include "llvm/CodeGen/MachineCodeEmitter.h"
#include "llvm/CodeGen/ObjectCodeEmitter.h"
#include "llvm/CodeGen/MachineCodeEmitter.h"
#include "llvm/CodeGen/MachineConstantPool.h"
-#include "llvm/Target/TargetAsmInfo.h"
+#include "llvm/MC/MCContext.h"
+#include "llvm/MC/MCSectionELF.h"
+#include "llvm/MC/MCAsmInfo.h"
+#include "llvm/Target/Mangler.h"
#include "llvm/Target/TargetData.h"
#include "llvm/Target/TargetELFWriterInfo.h"
+#include "llvm/Target/TargetLowering.h"
+#include "llvm/Target/TargetLoweringObjectFile.h"
#include "llvm/Target/TargetMachine.h"
-#include "llvm/Support/Mangler.h"
-#include "llvm/Support/Streams.h"
-#include "llvm/Support/raw_ostream.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/ErrorHandling.h"
-
+#include "llvm/Support/raw_ostream.h"
+#include "llvm/ADT/SmallString.h"
using namespace llvm;
char ELFWriter::ID = 0;
-/// AddELFWriter - Add the ELF writer to the function pass manager
-ObjectCodeEmitter *llvm::AddELFWriter(PassManagerBase &PM,
- raw_ostream &O,
- TargetMachine &TM) {
- ELFWriter *EW = new ELFWriter(O, TM);
- PM.add(EW);
- return EW->getObjectCodeEmitter();
-}
-
//===----------------------------------------------------------------------===//
// ELFWriter Implementation
//===----------------------------------------------------------------------===//
ELFWriter::ELFWriter(raw_ostream &o, TargetMachine &tm)
: MachineFunctionPass(&ID), O(o), TM(tm),
+ OutContext(*new MCContext(*TM.getMCAsmInfo())),
+ TLOF(TM.getTargetLowering()->getObjFileLowering()),
is64Bit(TM.getTargetData()->getPointerSizeInBits() == 64),
isLittleEndian(TM.getTargetData()->isLittleEndian()),
ElfHdr(isLittleEndian, is64Bit) {
- TAI = TM.getTargetAsmInfo();
+ MAI = TM.getMCAsmInfo();
TEW = TM.getELFWriterInfo();
// Create the object code emitter object for this target.
ELFWriter::~ELFWriter() {
delete ElfCE;
+ delete &OutContext;
+
+ while(!SymbolList.empty()) {
+ delete SymbolList.back();
+ SymbolList.pop_back();
+ }
+
+ while(!PrivateSyms.empty()) {
+ delete PrivateSyms.back();
+ PrivateSyms.pop_back();
+ }
+
+ while(!SectionList.empty()) {
+ delete SectionList.back();
+ SectionList.pop_back();
+ }
+
+ // Release the name mangler object.
+ delete Mang; Mang = 0;
}
// doInitialization - Emit the file header and all of the global variables for
// the module to the ELF file.
bool ELFWriter::doInitialization(Module &M) {
- Mang = new Mangler(M);
+ // Initialize TargetLoweringObjectFile.
+ const_cast<TargetLoweringObjectFile&>(TLOF).Initialize(OutContext, TM);
+
+ Mang = new Mangler(OutContext, *TM.getTargetData());
// ELF Header
// ----------
ElfHdr.emitByte(TEW->getEIClass()); // e_ident[EI_CLASS]
ElfHdr.emitByte(TEW->getEIData()); // e_ident[EI_DATA]
- ElfHdr.emitByte(EV_CURRENT); // e_ident[EI_VERSION]
+ ElfHdr.emitByte(ELF::EV_CURRENT); // e_ident[EI_VERSION]
ElfHdr.emitAlignment(16); // e_ident[EI_NIDENT-EI_PAD]
- ElfHdr.emitWord16(ET_REL); // e_type
+ ElfHdr.emitWord16(ELF::ET_REL); // e_type
ElfHdr.emitWord16(TEW->getEMachine()); // e_machine = target
- ElfHdr.emitWord32(EV_CURRENT); // e_version
+ ElfHdr.emitWord32(ELF::EV_CURRENT); // e_version
ElfHdr.emitWord(0); // e_entry, no entry point in .o file
ElfHdr.emitWord(0); // e_phoff, no program header for .o
ELFHdr_e_shoff_Offset = ElfHdr.size();
// Add the null section, which is required to be first in the file.
getNullSection();
+ // The first entry in the symtab is the null symbol and the second
+ // is a local symbol containing the module/file name
+ SymbolList.push_back(new ELFSym());
+ SymbolList.push_back(ELFSym::getFileSym());
+
return false;
}
+// AddPendingGlobalSymbol - Add a global to be processed and to
+// the global symbol lookup, use a zero index because the table
+// index will be determined later.
+void ELFWriter::AddPendingGlobalSymbol(const GlobalValue *GV,
+ bool AddToLookup /* = false */) {
+ PendingGlobals.insert(GV);
+ if (AddToLookup)
+ GblSymLookup[GV] = 0;
+}
+
+// AddPendingExternalSymbol - Add the external to be processed
+// and to the external symbol lookup, use a zero index because
+// the symbol table index will be determined later.
+void ELFWriter::AddPendingExternalSymbol(const char *External) {
+ PendingExternals.insert(External);
+ ExtSymLookup[External] = 0;
+}
+
+ELFSection &ELFWriter::getDataSection() {
+ const MCSectionELF *Data = (const MCSectionELF *)TLOF.getDataSection();
+ return getSection(Data->getSectionName(), Data->getType(),
+ Data->getFlags(), 4);
+}
+
+ELFSection &ELFWriter::getBSSSection() {
+ const MCSectionELF *BSS = (const MCSectionELF *)TLOF.getBSSSection();
+ return getSection(BSS->getSectionName(), BSS->getType(), BSS->getFlags(), 4);
+}
+
+// getCtorSection - Get the static constructor section
+ELFSection &ELFWriter::getCtorSection() {
+ const MCSectionELF *Ctor = (const MCSectionELF *)TLOF.getStaticCtorSection();
+ return getSection(Ctor->getSectionName(), Ctor->getType(), Ctor->getFlags());
+}
+
+// getDtorSection - Get the static destructor section
+ELFSection &ELFWriter::getDtorSection() {
+ const MCSectionELF *Dtor = (const MCSectionELF *)TLOF.getStaticDtorSection();
+ return getSection(Dtor->getSectionName(), Dtor->getType(), Dtor->getFlags());
+}
+
+// getTextSection - Get the text section for the specified function
+ELFSection &ELFWriter::getTextSection(const Function *F) {
+ const MCSectionELF *Text =
+ (const MCSectionELF *)TLOF.SectionForGlobal(F, Mang, TM);
+ return getSection(Text->getSectionName(), Text->getType(), Text->getFlags());
+}
+
+// getJumpTableSection - Get a read only section for constants when
+// emitting jump tables. TODO: add PIC support
+ELFSection &ELFWriter::getJumpTableSection() {
+ const MCSectionELF *JT =
+ (const MCSectionELF *)TLOF.getSectionForConstant(SectionKind::getReadOnly());
+ return getSection(JT->getSectionName(), JT->getType(), JT->getFlags(),
+ TM.getTargetData()->getPointerABIAlignment());
+}
+
+// getConstantPoolSection - Get a constant pool section based on the machine
+// constant pool entry type and relocation info.
+ELFSection &ELFWriter::getConstantPoolSection(MachineConstantPoolEntry &CPE) {
+ SectionKind Kind;
+ switch (CPE.getRelocationInfo()) {
+ default: llvm_unreachable("Unknown section kind");
+ case 2: Kind = SectionKind::getReadOnlyWithRel(); break;
+ case 1:
+ Kind = SectionKind::getReadOnlyWithRelLocal();
+ break;
+ case 0:
+ switch (TM.getTargetData()->getTypeAllocSize(CPE.getType())) {
+ case 4: Kind = SectionKind::getMergeableConst4(); break;
+ case 8: Kind = SectionKind::getMergeableConst8(); break;
+ case 16: Kind = SectionKind::getMergeableConst16(); break;
+ default: Kind = SectionKind::getMergeableConst(); break;
+ }
+ }
+
+ const MCSectionELF *CPSect =
+ (const MCSectionELF *)TLOF.getSectionForConstant(Kind);
+ return getSection(CPSect->getSectionName(), CPSect->getType(),
+ CPSect->getFlags(), CPE.getAlignment());
+}
+
+// getRelocSection - Return the relocation section of section 'S'. 'RelA'
+// is true if the relocation section contains entries with addends.
+ELFSection &ELFWriter::getRelocSection(ELFSection &S) {
+ unsigned SectionType = TEW->hasRelocationAddend() ?
+ ELF::SHT_RELA : ELF::SHT_REL;
+
+ std::string SectionName(".rel");
+ if (TEW->hasRelocationAddend())
+ SectionName.append("a");
+ SectionName.append(S.getName());
+
+ return getSection(SectionName, SectionType, 0, TEW->getPrefELFAlignment());
+}
+
// getGlobalELFVisibility - Returns the ELF specific visibility type
unsigned ELFWriter::getGlobalELFVisibility(const GlobalValue *GV) {
switch (GV->getVisibility()) {
default:
- LLVM_UNREACHABLE("unknown visibility type");
+ llvm_unreachable("unknown visibility type");
case GlobalValue::DefaultVisibility:
- return ELFSym::STV_DEFAULT;
+ return ELF::STV_DEFAULT;
case GlobalValue::HiddenVisibility:
- return ELFSym::STV_HIDDEN;
+ return ELF::STV_HIDDEN;
case GlobalValue::ProtectedVisibility:
- return ELFSym::STV_PROTECTED;
+ return ELF::STV_PROTECTED;
}
return 0;
}
// getGlobalELFBinding - Returns the ELF specific binding type
unsigned ELFWriter::getGlobalELFBinding(const GlobalValue *GV) {
if (GV->hasInternalLinkage())
- return ELFSym::STB_LOCAL;
+ return ELF::STB_LOCAL;
- if (GV->hasWeakLinkage())
- return ELFSym::STB_WEAK;
+ if (GV->isWeakForLinker() && !GV->hasCommonLinkage())
+ return ELF::STB_WEAK;
- return ELFSym::STB_GLOBAL;
+ return ELF::STB_GLOBAL;
}
// getGlobalELFType - Returns the ELF specific type for a global
unsigned ELFWriter::getGlobalELFType(const GlobalValue *GV) {
if (GV->isDeclaration())
- return ELFSym::STT_NOTYPE;
+ return ELF::STT_NOTYPE;
if (isa<Function>(GV))
- return ELFSym::STT_FUNC;
-
- return ELFSym::STT_OBJECT;
-}
-
-// getElfSectionFlags - Get the ELF Section Header flags based
-// on the flags defined in ELFTargetAsmInfo.
-unsigned ELFWriter::getElfSectionFlags(unsigned Flags) {
- unsigned ElfSectionFlags = ELFSection::SHF_ALLOC;
-
- if (Flags & SectionFlags::Code)
- ElfSectionFlags |= ELFSection::SHF_EXECINSTR;
- if (Flags & SectionFlags::Writeable)
- ElfSectionFlags |= ELFSection::SHF_WRITE;
- if (Flags & SectionFlags::Mergeable)
- ElfSectionFlags |= ELFSection::SHF_MERGE;
- if (Flags & SectionFlags::TLS)
- ElfSectionFlags |= ELFSection::SHF_TLS;
- if (Flags & SectionFlags::Strings)
- ElfSectionFlags |= ELFSection::SHF_STRINGS;
-
- return ElfSectionFlags;
-}
-
-// isELFUndefSym - the symbol has no section and must be placed in
-// the symbol table with a reference to the null section.
-static bool isELFUndefSym(const GlobalValue *GV) {
- return GV->isDeclaration();
-}
+ return ELF::STT_FUNC;
-// isELFBssSym - for an undef or null value, the symbol must go to a bss
-// section if it's not weak for linker, otherwise it's a common sym.
-static bool isELFBssSym(const GlobalValue *GV) {
- return (!GV->isDeclaration() &&
- (GV->isNullValue() || isa<UndefValue>(GV)) &&
- !GV->isWeakForLinker());
+ return ELF::STT_OBJECT;
}
-// isELFCommonSym - for an undef or null value, the symbol must go to a
-// common section if it's weak for linker, otherwise bss.
-static bool isELFCommonSym(const GlobalValue *GV) {
- return (!GV->isDeclaration() &&
- (GV->isNullValue() || isa<UndefValue>(GV))
- && GV->isWeakForLinker());
+// IsELFUndefSym - True if the global value must be marked as a symbol
+// which points to a SHN_UNDEF section. This means that the symbol has
+// no definition on the module.
+static bool IsELFUndefSym(const GlobalValue *GV) {
+ return GV->isDeclaration() || (isa<Function>(GV));
}
-// isELFDataSym - if the symbol is an initialized but no null constant
-// it must go to some kind of data section gathered from TAI
-static bool isELFDataSym(const GlobalValue *GV) {
- return (!GV->isDeclaration() &&
- !(GV->isNullValue() || isa<UndefValue>(GV)));
+// AddToSymbolList - Update the symbol lookup and If the symbol is
+// private add it to PrivateSyms list, otherwise to SymbolList.
+void ELFWriter::AddToSymbolList(ELFSym *GblSym) {
+ assert(GblSym->isGlobalValue() && "Symbol must be a global value");
+
+ const GlobalValue *GV = GblSym->getGlobalValue();
+ if (GV->hasPrivateLinkage()) {
+ // For a private symbols, keep track of the index inside
+ // the private list since it will never go to the symbol
+ // table and won't be patched up later.
+ PrivateSyms.push_back(GblSym);
+ GblSymLookup[GV] = PrivateSyms.size()-1;
+ } else {
+ // Non private symbol are left with zero indices until
+ // they are patched up during the symbol table emition
+ // (where the indicies are created).
+ SymbolList.push_back(GblSym);
+ GblSymLookup[GV] = 0;
+ }
}
// EmitGlobal - Choose the right section for global and emit it
void ELFWriter::EmitGlobal(const GlobalValue *GV) {
+ // Check if the referenced symbol is already emitted
+ if (GblSymLookup.find(GV) != GblSymLookup.end())
+ return;
+
// Handle ELF Bind, Visibility and Type for the current symbol
unsigned SymBind = getGlobalELFBinding(GV);
- ELFSym GblSym(GV);
- GblSym.setBind(SymBind);
- GblSym.setVisibility(getGlobalELFVisibility(GV));
- GblSym.setType(getGlobalELFType(GV));
+ unsigned SymType = getGlobalELFType(GV);
+ bool IsUndefSym = IsELFUndefSym(GV);
- if (isELFUndefSym(GV)) {
- GblSym.SectionIdx = ELFSection::SHN_UNDEF;
- } else {
+ ELFSym *GblSym = IsUndefSym ? ELFSym::getUndefGV(GV, SymBind)
+ : ELFSym::getGV(GV, SymBind, SymType, getGlobalELFVisibility(GV));
+
+ if (!IsUndefSym) {
assert(isa<GlobalVariable>(GV) && "GV not a global variable!");
const GlobalVariable *GVar = dyn_cast<GlobalVariable>(GV);
- // Get ELF section from TAI
- const Section *S = TAI->SectionForGlobal(GV);
- unsigned SectionFlags = getElfSectionFlags(S->getFlags());
+ // Handle special llvm globals
+ if (EmitSpecialLLVMGlobal(GVar))
+ return;
+
+ // Get the ELF section where this global belongs from TLOF
+ const MCSectionELF *S =
+ (const MCSectionELF *)TLOF.SectionForGlobal(GV, Mang, TM);
+ ELFSection &ES =
+ getSection(S->getSectionName(), S->getType(), S->getFlags());
+ SectionKind Kind = S->getKind();
// The symbol align should update the section alignment if needed
const TargetData *TD = TM.getTargetData();
unsigned Align = TD->getPreferredAlignment(GVar);
unsigned Size = TD->getTypeAllocSize(GVar->getInitializer()->getType());
- GblSym.Size = Size;
+ GblSym->Size = Size;
- if (isELFCommonSym(GV)) {
- GblSym.SectionIdx = ELFSection::SHN_COMMON;
- getSection(S->getName(), ELFSection::SHT_NOBITS, SectionFlags, 1);
+ if (S->HasCommonSymbols()) { // Symbol must go to a common section
+ GblSym->SectionIdx = ELF::SHN_COMMON;
// A new linkonce section is created for each global in the
// common section, the default alignment is 1 and the symbol
// value contains its alignment.
- GblSym.Value = Align;
+ ES.Align = 1;
+ GblSym->Value = Align;
- } else if (isELFBssSym(GV)) {
- ELFSection &ES =
- getSection(S->getName(), ELFSection::SHT_NOBITS, SectionFlags);
- GblSym.SectionIdx = ES.SectionIdx;
+ } else if (Kind.isBSS() || Kind.isThreadBSS()) { // Symbol goes to BSS.
+ GblSym->SectionIdx = ES.SectionIdx;
// Update the size with alignment and the next object can
// start in the right offset in the section
if (Align) ES.Size = (ES.Size + Align-1) & ~(Align-1);
ES.Align = std::max(ES.Align, Align);
- // GblSym.Value should contain the virtual offset inside the section.
+ // GblSym->Value should contain the virtual offset inside the section.
// Virtual because the BSS space is not allocated on ELF objects
- GblSym.Value = ES.Size;
+ GblSym->Value = ES.Size;
ES.Size += Size;
- } else if (isELFDataSym(GV)) {
- ELFSection &ES =
- getSection(S->getName(), ELFSection::SHT_PROGBITS, SectionFlags);
- GblSym.SectionIdx = ES.SectionIdx;
+ } else { // The symbol must go to some kind of data section
+ GblSym->SectionIdx = ES.SectionIdx;
- // GblSym.Value should contain the symbol offset inside the section,
+ // GblSym->Value should contain the symbol offset inside the section,
// and all symbols should start on their required alignment boundary
ES.Align = std::max(ES.Align, Align);
- GblSym.Value = (ES.size() + (Align-1)) & (-Align);
- ES.emitAlignment(ES.Align);
+ ES.emitAlignment(Align);
+ GblSym->Value = ES.size();
// Emit the global to the data section 'ES'
EmitGlobalConstant(GVar->getInitializer(), ES);
}
}
- // Local symbols should come first on the symbol table.
- if (!GV->hasPrivateLinkage()) {
- if (SymBind == ELFSym::STB_LOCAL)
- SymbolList.push_front(GblSym);
- else
- SymbolList.push_back(GblSym);
- }
+ AddToSymbolList(GblSym);
}
void ELFWriter::EmitGlobalConstantStruct(const ConstantStruct *CVS,
// Insert padding - this may include padding to increase the size of the
// current field up to the ABI size (if the struct is not packed) as well
// as padding to ensure that the next field starts at the right offset.
- for (unsigned p=0; p < padSize; p++)
- GblS.emitByte(0);
+ GblS.emitZeros(padSize);
}
assert(sizeSoFar == cvsLayout->getSizeInBytes() &&
"Layout of constant struct may be incorrect!");
unsigned Size = TD->getTypeAllocSize(CV->getType());
if (const ConstantArray *CVA = dyn_cast<ConstantArray>(CV)) {
- if (CVA->isString()) {
- std::string GblStr = CVA->getAsString();
- GblStr.resize(GblStr.size()-1);
- GblS.emitString(GblStr);
- } else { // Not a string. Print the values in successive locations
- for (unsigned i = 0, e = CVA->getNumOperands(); i != e; ++i)
- EmitGlobalConstant(CVA->getOperand(i), GblS);
- }
+ for (unsigned i = 0, e = CVA->getNumOperands(); i != e; ++i)
+ EmitGlobalConstant(CVA->getOperand(i), GblS);
+ return;
+ } else if (isa<ConstantAggregateZero>(CV)) {
+ GblS.emitZeros(Size);
return;
} else if (const ConstantStruct *CVS = dyn_cast<ConstantStruct>(CV)) {
EmitGlobalConstantStruct(CVS, GblS);
return;
} else if (const ConstantFP *CFP = dyn_cast<ConstantFP>(CV)) {
- uint64_t Val = CFP->getValueAPF().bitcastToAPInt().getZExtValue();
- if (CFP->getType() == Type::DoubleTy)
- GblS.emitWord64(Val);
- else if (CFP->getType() == Type::FloatTy)
- GblS.emitWord32(Val);
- else if (CFP->getType() == Type::X86_FP80Ty) {
- LLVM_UNREACHABLE("X86_FP80Ty global emission not implemented");
- } else if (CFP->getType() == Type::PPC_FP128Ty)
- LLVM_UNREACHABLE("PPC_FP128Ty global emission not implemented");
+ APInt Val = CFP->getValueAPF().bitcastToAPInt();
+ if (CFP->getType()->isDoubleTy())
+ GblS.emitWord64(Val.getZExtValue());
+ else if (CFP->getType()->isFloatTy())
+ GblS.emitWord32(Val.getZExtValue());
+ else if (CFP->getType()->isX86_FP80Ty()) {
+ unsigned PadSize = TD->getTypeAllocSize(CFP->getType())-
+ TD->getTypeStoreSize(CFP->getType());
+ GblS.emitWordFP80(Val.getRawData(), PadSize);
+ } else if (CFP->getType()->isPPC_FP128Ty())
+ llvm_unreachable("PPC_FP128Ty global emission not implemented");
return;
} else if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV)) {
- if (Size == 4)
+ if (Size == 1)
+ GblS.emitByte(CI->getZExtValue());
+ else if (Size == 2)
+ GblS.emitWord16(CI->getZExtValue());
+ else if (Size == 4)
GblS.emitWord32(CI->getZExtValue());
- else if (Size == 8)
- GblS.emitWord64(CI->getZExtValue());
- else
- LLVM_UNREACHABLE("LargeInt global emission not implemented");
+ else
+ EmitGlobalConstantLargeInt(CI, GblS);
return;
} else if (const ConstantVector *CP = dyn_cast<ConstantVector>(CV)) {
const VectorType *PTy = CP->getType();
for (unsigned I = 0, E = PTy->getNumElements(); I < E; ++I)
EmitGlobalConstant(CP->getOperand(I), GblS);
return;
+ } else if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV)) {
+ // Resolve a constant expression which returns a (Constant, Offset)
+ // pair. If 'Res.first' is a GlobalValue, emit a relocation with
+ // the offset 'Res.second', otherwise emit a global constant like
+ // it is always done for not contant expression types.
+ CstExprResTy Res = ResolveConstantExpr(CE);
+ const Constant *Op = Res.first;
+
+ if (isa<GlobalValue>(Op))
+ EmitGlobalDataRelocation(cast<const GlobalValue>(Op),
+ TD->getTypeAllocSize(Op->getType()),
+ GblS, Res.second);
+ else
+ EmitGlobalConstant(Op, GblS);
+
+ return;
+ } else if (CV->getType()->getTypeID() == Type::PointerTyID) {
+ // Fill the data entry with zeros or emit a relocation entry
+ if (isa<ConstantPointerNull>(CV))
+ GblS.emitZeros(Size);
+ else
+ EmitGlobalDataRelocation(cast<const GlobalValue>(CV),
+ Size, GblS);
+ return;
+ } else if (const GlobalValue *GV = dyn_cast<GlobalValue>(CV)) {
+ // This is a constant address for a global variable or function and
+ // therefore must be referenced using a relocation entry.
+ EmitGlobalDataRelocation(GV, Size, GblS);
+ return;
}
- LLVM_UNREACHABLE("unknown global constant");
+
+ std::string msg;
+ raw_string_ostream ErrorMsg(msg);
+ ErrorMsg << "Constant unimp for type: " << *CV->getType();
+ report_fatal_error(ErrorMsg.str());
}
+// ResolveConstantExpr - Resolve the constant expression until it stop
+// yielding other constant expressions.
+CstExprResTy ELFWriter::ResolveConstantExpr(const Constant *CV) {
+ const TargetData *TD = TM.getTargetData();
+
+ // There ins't constant expression inside others anymore
+ if (!isa<ConstantExpr>(CV))
+ return std::make_pair(CV, 0);
+
+ const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV);
+ switch (CE->getOpcode()) {
+ case Instruction::BitCast:
+ return ResolveConstantExpr(CE->getOperand(0));
+
+ case Instruction::GetElementPtr: {
+ const Constant *ptrVal = CE->getOperand(0);
+ SmallVector<Value*, 8> idxVec(CE->op_begin()+1, CE->op_end());
+ int64_t Offset = TD->getIndexedOffset(ptrVal->getType(), &idxVec[0],
+ idxVec.size());
+ return std::make_pair(ptrVal, Offset);
+ }
+ case Instruction::IntToPtr: {
+ Constant *Op = CE->getOperand(0);
+ Op = ConstantExpr::getIntegerCast(Op, TD->getIntPtrType(CV->getContext()),
+ false/*ZExt*/);
+ return ResolveConstantExpr(Op);
+ }
+ case Instruction::PtrToInt: {
+ Constant *Op = CE->getOperand(0);
+ const Type *Ty = CE->getType();
+
+ // We can emit the pointer value into this slot if the slot is an
+ // integer slot greater or equal to the size of the pointer.
+ if (TD->getTypeAllocSize(Ty) == TD->getTypeAllocSize(Op->getType()))
+ return ResolveConstantExpr(Op);
+
+ llvm_unreachable("Integer size less then pointer size");
+ }
+ case Instruction::Add:
+ case Instruction::Sub: {
+ // Only handle cases where there's a constant expression with GlobalValue
+ // as first operand and ConstantInt as second, which are the cases we can
+ // solve direclty using a relocation entry. GlobalValue=Op0, CstInt=Op1
+ // 1) Instruction::Add => (global) + CstInt
+ // 2) Instruction::Sub => (global) + -CstInt
+ const Constant *Op0 = CE->getOperand(0);
+ const Constant *Op1 = CE->getOperand(1);
+ assert(isa<ConstantInt>(Op1) && "Op1 must be a ConstantInt");
+
+ CstExprResTy Res = ResolveConstantExpr(Op0);
+ assert(isa<GlobalValue>(Res.first) && "Op0 must be a GlobalValue");
+
+ const APInt &RHS = cast<ConstantInt>(Op1)->getValue();
+ switch (CE->getOpcode()) {
+ case Instruction::Add:
+ return std::make_pair(Res.first, RHS.getSExtValue());
+ case Instruction::Sub:
+ return std::make_pair(Res.first, (-RHS).getSExtValue());
+ }
+ }
+ }
+
+ report_fatal_error(CE->getOpcodeName() +
+ StringRef(": Unsupported ConstantExpr type"));
+
+ return std::make_pair(CV, 0); // silence warning
+}
+
+void ELFWriter::EmitGlobalDataRelocation(const GlobalValue *GV, unsigned Size,
+ ELFSection &GblS, int64_t Offset) {
+ // Create the relocation entry for the global value
+ MachineRelocation MR =
+ MachineRelocation::getGV(GblS.getCurrentPCOffset(),
+ TEW->getAbsoluteLabelMachineRelTy(),
+ const_cast<GlobalValue*>(GV),
+ Offset);
+
+ // Fill the data entry with zeros
+ GblS.emitZeros(Size);
+
+ // Add the relocation entry for the current data section
+ GblS.addRelocation(MR);
+}
+
+void ELFWriter::EmitGlobalConstantLargeInt(const ConstantInt *CI,
+ ELFSection &S) {
+ const TargetData *TD = TM.getTargetData();
+ unsigned BitWidth = CI->getBitWidth();
+ assert(isPowerOf2_32(BitWidth) &&
+ "Non-power-of-2-sized integers not handled!");
+
+ const uint64_t *RawData = CI->getValue().getRawData();
+ uint64_t Val = 0;
+ for (unsigned i = 0, e = BitWidth / 64; i != e; ++i) {
+ Val = (TD->isBigEndian()) ? RawData[e - i - 1] : RawData[i];
+ S.emitWord64(Val);
+ }
+}
+
+/// EmitSpecialLLVMGlobal - Check to see if the specified global is a
+/// special global used by LLVM. If so, emit it and return true, otherwise
+/// do nothing and return false.
+bool ELFWriter::EmitSpecialLLVMGlobal(const GlobalVariable *GV) {
+ if (GV->getName() == "llvm.used")
+ llvm_unreachable("not implemented yet");
+
+ // Ignore debug and non-emitted data. This handles llvm.compiler.used.
+ if (GV->getSection() == "llvm.metadata" ||
+ GV->hasAvailableExternallyLinkage())
+ return true;
+
+ if (!GV->hasAppendingLinkage()) return false;
+
+ assert(GV->hasInitializer() && "Not a special LLVM global!");
+
+ const TargetData *TD = TM.getTargetData();
+ unsigned Align = TD->getPointerPrefAlignment();
+ if (GV->getName() == "llvm.global_ctors") {
+ ELFSection &Ctor = getCtorSection();
+ Ctor.emitAlignment(Align);
+ EmitXXStructorList(GV->getInitializer(), Ctor);
+ return true;
+ }
+
+ if (GV->getName() == "llvm.global_dtors") {
+ ELFSection &Dtor = getDtorSection();
+ Dtor.emitAlignment(Align);
+ EmitXXStructorList(GV->getInitializer(), Dtor);
+ return true;
+ }
+
+ return false;
+}
+
+/// EmitXXStructorList - Emit the ctor or dtor list. This just emits out the
+/// function pointers, ignoring the init priority.
+void ELFWriter::EmitXXStructorList(Constant *List, ELFSection &Xtor) {
+ // Should be an array of '{ int, void ()* }' structs. The first value is the
+ // init priority, which we ignore.
+ if (!isa<ConstantArray>(List)) return;
+ ConstantArray *InitList = cast<ConstantArray>(List);
+ for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i)
+ if (ConstantStruct *CS = dyn_cast<ConstantStruct>(InitList->getOperand(i))){
+ if (CS->getNumOperands() != 2) return; // Not array of 2-element structs.
+
+ if (CS->getOperand(1)->isNullValue())
+ return; // Found a null terminator, exit printing.
+ // Emit the function pointer.
+ EmitGlobalConstant(CS->getOperand(1), Xtor);
+ }
+}
bool ELFWriter::runOnMachineFunction(MachineFunction &MF) {
// Nothing to do here, this is all done through the ElfCE object above.
// Build and emit data, bss and "common" sections.
for (Module::global_iterator I = M.global_begin(), E = M.global_end();
- I != E; ++I) {
+ I != E; ++I)
EmitGlobal(I);
- GblSymLookup[I] = 0;
- }
// Emit all pending globals
- // TODO: this should be done only for referenced symbols
- for (SetVector<GlobalValue*>::const_iterator I = PendingGlobals.begin(),
- E = PendingGlobals.end(); I != E; ++I) {
-
- // No need to emit the symbol again
- if (GblSymLookup.find(*I) != GblSymLookup.end())
- continue;
-
+ for (PendingGblsIter I = PendingGlobals.begin(), E = PendingGlobals.end();
+ I != E; ++I)
EmitGlobal(*I);
- GblSymLookup[*I] = 0;
- }
-
- // Emit non-executable stack note
- if (TAI->getNonexecutableStackDirective())
- getNonExecStackSection();
-
- // Emit a symbol for each section created until now
- for (std::map<std::string, ELFSection*>::iterator I = SectionLookup.begin(),
- E = SectionLookup.end(); I != E; ++I) {
- ELFSection *ES = I->second;
- // Skip null section
- if (ES->SectionIdx == 0) continue;
-
- ELFSym SectionSym(0);
- SectionSym.SectionIdx = ES->SectionIdx;
- SectionSym.Size = 0;
- SectionSym.setBind(ELFSym::STB_LOCAL);
- SectionSym.setType(ELFSym::STT_SECTION);
- SectionSym.setVisibility(ELFSym::STV_DEFAULT);
-
- // Local symbols go in the list front
- SymbolList.push_front(SectionSym);
+ // Emit all pending externals
+ for (PendingExtsIter I = PendingExternals.begin(), E = PendingExternals.end();
+ I != E; ++I)
+ SymbolList.push_back(ELFSym::getExtSym(*I));
+
+ // Emit a symbol for each section created until now, skip null section
+ for (unsigned i = 1, e = SectionList.size(); i < e; ++i) {
+ ELFSection &ES = *SectionList[i];
+ ELFSym *SectionSym = ELFSym::getSectionSym();
+ SectionSym->SectionIdx = ES.SectionIdx;
+ SymbolList.push_back(SectionSym);
+ ES.Sym = SymbolList.back();
}
// Emit string table
- EmitStringTable();
+ EmitStringTable(M.getModuleIdentifier());
// Emit the symbol table now, if non-empty.
EmitSymbolTable();
// Dump the sections and section table to the .o file.
OutputSectionsAndSectionTable();
- // We are done with the abstract symbols.
- SectionList.clear();
- NumSections = 0;
-
- // Release the name mangler object.
- delete Mang; Mang = 0;
return false;
}
+// RelocateField - Patch relocatable field with 'Offset' in 'BO'
+// using a 'Value' of known 'Size'
+void ELFWriter::RelocateField(BinaryObject &BO, uint32_t Offset,
+ int64_t Value, unsigned Size) {
+ if (Size == 32)
+ BO.fixWord32(Value, Offset);
+ else if (Size == 64)
+ BO.fixWord64(Value, Offset);
+ else
+ llvm_unreachable("don't know howto patch relocatable field");
+}
+
/// EmitRelocations - Emit relocations
void ELFWriter::EmitRelocations() {
+ // True if the target uses the relocation entry to hold the addend,
+ // otherwise the addend is written directly to the relocatable field.
+ bool HasRelA = TEW->hasRelocationAddend();
+
// Create Relocation sections for each section which needs it.
- for (std::list<ELFSection>::iterator I = SectionList.begin(),
- E = SectionList.end(); I != E; ++I) {
+ for (unsigned i=0, e=SectionList.size(); i != e; ++i) {
+ ELFSection &S = *SectionList[i];
// This section does not have relocations
- if (!I->hasRelocations()) continue;
-
- // Get the relocation section for section 'I'
- bool HasRelA = TEW->hasRelocationAddend();
- ELFSection &RelSec = getRelocSection(I->getName(), HasRelA,
- TEW->getPrefELFAlignment());
+ if (!S.hasRelocations()) continue;
+ ELFSection &RelSec = getRelocSection(S);
// 'Link' - Section hdr idx of the associated symbol table
// 'Info' - Section hdr idx of the section to which the relocation applies
ELFSection &SymTab = getSymbolTableSection();
RelSec.Link = SymTab.SectionIdx;
- RelSec.Info = I->SectionIdx;
+ RelSec.Info = S.SectionIdx;
RelSec.EntSize = TEW->getRelocationEntrySize();
// Get the relocations from Section
- std::vector<MachineRelocation> Relos = I->getRelocations();
+ std::vector<MachineRelocation> Relos = S.getRelocations();
for (std::vector<MachineRelocation>::iterator MRI = Relos.begin(),
MRE = Relos.end(); MRI != MRE; ++MRI) {
MachineRelocation &MR = *MRI;
- // Offset from the start of the section containing the symbol
- unsigned Offset = MR.getMachineCodeOffset();
+ // Relocatable field offset from the section start
+ unsigned RelOffset = MR.getMachineCodeOffset();
// Symbol index in the symbol table
unsigned SymIdx = 0;
- // Target specific ELF relocation type
+ // Target specific relocation field type and size
unsigned RelType = TEW->getRelocationType(MR.getRelocationType());
-
- // Constant addend used to compute the value to be stored
- // into the relocatable field
+ unsigned RelTySize = TEW->getRelocationTySize(RelType);
int64_t Addend = 0;
// There are several machine relocations types, and each one of
// them needs a different approach to retrieve the symbol table index.
if (MR.isGlobalValue()) {
const GlobalValue *G = MR.getGlobalValue();
+ int64_t GlobalOffset = MR.getConstantVal();
SymIdx = GblSymLookup[G];
- Addend = TEW->getAddendForRelTy(RelType);
+ if (G->hasPrivateLinkage()) {
+ // If the target uses a section offset in the relocation:
+ // SymIdx + Addend = section sym for global + section offset
+ unsigned SectionIdx = PrivateSyms[SymIdx]->SectionIdx;
+ Addend = PrivateSyms[SymIdx]->Value + GlobalOffset;
+ SymIdx = SectionList[SectionIdx]->getSymbolTableIndex();
+ } else {
+ Addend = TEW->getDefaultAddendForRelTy(RelType, GlobalOffset);
+ }
+ } else if (MR.isExternalSymbol()) {
+ const char *ExtSym = MR.getExternalSymbol();
+ SymIdx = ExtSymLookup[ExtSym];
+ Addend = TEW->getDefaultAddendForRelTy(RelType);
} else {
+ // Get the symbol index for the section symbol
unsigned SectionIdx = MR.getConstantVal();
- // TODO: use a map for this.
- for (std::list<ELFSym>::iterator I = SymbolList.begin(),
- E = SymbolList.end(); I != E; ++I)
- if ((SectionIdx == I->SectionIdx) &&
- (I->getType() == ELFSym::STT_SECTION)) {
- SymIdx = I->SymTabIdx;
- break;
- }
- Addend = (uint64_t)MR.getResultPointer();
+ SymIdx = SectionList[SectionIdx]->getSymbolTableIndex();
+
+ // The symbol offset inside the section
+ int64_t SymOffset = (int64_t)MR.getResultPointer();
+
+ // For pc relative relocations where symbols are defined in the same
+ // section they are referenced, ignore the relocation entry and patch
+ // the relocatable field with the symbol offset directly.
+ if (S.SectionIdx == SectionIdx && TEW->isPCRelativeRel(RelType)) {
+ int64_t Value = TEW->computeRelocation(SymOffset, RelOffset, RelType);
+ RelocateField(S, RelOffset, Value, RelTySize);
+ continue;
+ }
+
+ Addend = TEW->getDefaultAddendForRelTy(RelType, SymOffset);
}
+ // The target without addend on the relocation symbol must be
+ // patched in the relocation place itself to contain the addend
+ // otherwise write zeros to make sure there is no garbage there
+ RelocateField(S, RelOffset, HasRelA ? 0 : Addend, RelTySize);
+
// Get the relocation entry and emit to the relocation section
- ELFRelocation Rel(Offset, SymIdx, RelType, HasRelA, Addend);
+ ELFRelocation Rel(RelOffset, SymIdx, RelType, HasRelA, Addend);
EmitRelocation(RelSec, Rel, HasRelA);
}
}
/// EmitStringTable - If the current symbol table is non-empty, emit the string
/// table for it
-void ELFWriter::EmitStringTable() {
+void ELFWriter::EmitStringTable(const std::string &ModuleName) {
if (!SymbolList.size()) return; // Empty symbol table.
ELFSection &StrTab = getStringTableSection();
// Set the zero'th symbol to a null byte, as required.
StrTab.emitByte(0);
- // Walk on the symbol list and write symbol names into the
- // string table.
+ // Walk on the symbol list and write symbol names into the string table.
unsigned Index = 1;
- for (std::list<ELFSym>::iterator I = SymbolList.begin(),
- E = SymbolList.end(); I != E; ++I) {
+ for (ELFSymIter I=SymbolList.begin(), E=SymbolList.end(); I != E; ++I) {
+ ELFSym &Sym = *(*I);
- // Use the name mangler to uniquify the LLVM symbol.
std::string Name;
- if (I->GV) Name.append(Mang->getValueName(I->GV));
+ if (Sym.isGlobalValue()) {
+ SmallString<40> NameStr;
+ Mang->getNameWithPrefix(NameStr, Sym.getGlobalValue(), false);
+ Name.append(NameStr.begin(), NameStr.end());
+ } else if (Sym.isExternalSym())
+ Name.append(Sym.getExternalSymbol());
+ else if (Sym.isFileType())
+ Name.append(ModuleName);
if (Name.empty()) {
- I->NameIdx = 0;
+ Sym.NameIdx = 0;
} else {
- I->NameIdx = Index;
+ Sym.NameIdx = Index;
StrTab.emitString(Name);
// Keep track of the number of bytes emitted to this section.
StrTab.Size = Index;
}
+// SortSymbols - On the symbol table local symbols must come before
+// all other symbols with non-local bindings. The return value is
+// the position of the first non local symbol.
+unsigned ELFWriter::SortSymbols() {
+ unsigned FirstNonLocalSymbol;
+ std::vector<ELFSym*> LocalSyms, OtherSyms;
+
+ for (ELFSymIter I=SymbolList.begin(), E=SymbolList.end(); I != E; ++I) {
+ if ((*I)->isLocalBind())
+ LocalSyms.push_back(*I);
+ else
+ OtherSyms.push_back(*I);
+ }
+ SymbolList.clear();
+ FirstNonLocalSymbol = LocalSyms.size();
+
+ for (unsigned i = 0; i < FirstNonLocalSymbol; ++i)
+ SymbolList.push_back(LocalSyms[i]);
+
+ for (ELFSymIter I=OtherSyms.begin(), E=OtherSyms.end(); I != E; ++I)
+ SymbolList.push_back(*I);
+
+ LocalSyms.clear();
+ OtherSyms.clear();
+
+ return FirstNonLocalSymbol;
+}
+
/// EmitSymbolTable - Emit the symbol table itself.
void ELFWriter::EmitSymbolTable() {
if (!SymbolList.size()) return; // Empty symbol table.
- unsigned FirstNonLocalSymbol = 1;
// Now that we have emitted the string table and know the offset into the
// string table of each symbol, emit the symbol table itself.
ELFSection &SymTab = getSymbolTableSection();
// Size of each symtab entry.
SymTab.EntSize = TEW->getSymTabEntrySize();
- // The first entry in the symtab is the null symbol
- ELFSym NullSym = ELFSym(0);
- EmitSymbol(SymTab, NullSym);
+ // Reorder the symbol table with local symbols first!
+ unsigned FirstNonLocalSymbol = SortSymbols();
- // Emit all the symbols to the symbol table. Skip the null
- // symbol, cause it's emitted already
- unsigned Index = 1;
- for (std::list<ELFSym>::iterator I = SymbolList.begin(),
- E = SymbolList.end(); I != E; ++I, ++Index) {
- // Keep track of the first non-local symbol
- if (I->getBind() == ELFSym::STB_LOCAL)
- FirstNonLocalSymbol++;
+ // Emit all the symbols to the symbol table.
+ for (unsigned i = 0, e = SymbolList.size(); i < e; ++i) {
+ ELFSym &Sym = *SymbolList[i];
// Emit symbol to the symbol table
- EmitSymbol(SymTab, *I);
+ EmitSymbol(SymTab, Sym);
- // Record the symbol table index for each global value
- if (I->GV)
- GblSymLookup[I->GV] = Index;
+ // Record the symbol table index for each symbol
+ if (Sym.isGlobalValue())
+ GblSymLookup[Sym.getGlobalValue()] = i;
+ else if (Sym.isExternalSym())
+ ExtSymLookup[Sym.getExternalSymbol()] = i;
// Keep track on the symbol index into the symbol table
- I->SymTabIdx = Index;
+ Sym.SymTabIdx = i;
}
+ // One greater than the symbol table index of the last local symbol
SymTab.Info = FirstNonLocalSymbol;
SymTab.Size = SymTab.size();
}
// the string table.
unsigned Index = 0;
- for (std::list<ELFSection>::iterator I = SectionList.begin(),
- E = SectionList.end(); I != E; ++I) {
+ for (ELFSectionIter I=SectionList.begin(), E=SectionList.end(); I != E; ++I) {
+ ELFSection &S = *(*I);
// Set the index into the table. Note if we have lots of entries with
// common suffixes, we could memoize them here if we cared.
- I->NameIdx = Index;
- SHStrTab.emitString(I->getName());
+ S.NameIdx = Index;
+ SHStrTab.emitString(S.getName());
// Keep track of the number of bytes emitted to this section.
- Index += I->getName().size()+1;
+ Index += S.getName().size()+1;
}
// Set the size of .shstrtab now that we know what it is.
// Pass #1: Compute the file offset for each section.
size_t FileOff = ElfHdr.size(); // File header first.
- // Adjust alignment of all section if needed.
- for (std::list<ELFSection>::iterator I = SectionList.begin(),
- E = SectionList.end(); I != E; ++I) {
-
- // Section idx 0 has 0 offset
- if (!I->SectionIdx)
- continue;
-
- if (!I->size()) {
- I->Offset = FileOff;
+ // Adjust alignment of all section if needed, skip the null section.
+ for (unsigned i=1, e=SectionList.size(); i < e; ++i) {
+ ELFSection &ES = *SectionList[i];
+ if (!ES.size()) {
+ ES.Offset = FileOff;
continue;
}
// Update Section size
- if (!I->Size)
- I->Size = I->size();
+ if (!ES.Size)
+ ES.Size = ES.size();
// Align FileOff to whatever the alignment restrictions of the section are.
- if (I->Align)
- FileOff = (FileOff+I->Align-1) & ~(I->Align-1);
+ if (ES.Align)
+ FileOff = (FileOff+ES.Align-1) & ~(ES.Align-1);
- I->Offset = FileOff;
- FileOff += I->Size;
+ ES.Offset = FileOff;
+ FileOff += ES.Size;
}
// Align Section Header.
BinaryObject SHdrTable(isLittleEndian, is64Bit);
// Emit all of sections to the file and build the section header table.
- while (!SectionList.empty()) {
- ELFSection &S = *SectionList.begin();
- DOUT << "SectionIdx: " << S.SectionIdx << ", Name: " << S.getName()
- << ", Size: " << S.Size << ", Offset: " << S.Offset
- << ", SectionData Size: " << S.size() << "\n";
+ for (ELFSectionIter I=SectionList.begin(), E=SectionList.end(); I != E; ++I) {
+ ELFSection &S = *(*I);
+ DEBUG(dbgs() << "SectionIdx: " << S.SectionIdx << ", Name: " << S.getName()
+ << ", Size: " << S.Size << ", Offset: " << S.Offset
+ << ", SectionData Size: " << S.size() << "\n");
// Align FileOff to whatever the alignment restrictions of the section are.
if (S.size()) {
}
EmitSectionHeader(SHdrTable, S);
- SectionList.pop_front();
}
// Align output for the section table.
projects / oota-llvm.git / blobdiff