//
// The LLVM Compiler Infrastructure
//
-// This file was developed by the LLVM research group and is distributed under
-// the University of Illinois Open Source License. See LICENSE.TXT for details.
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// #3. ".bss" entry - global variables without initializers. [ if needed ]
// ...
// #N. ".shstrtab" entry - String table for the section names.
-
-//
-// NOTE: This code should eventually be extended to support 64-bit ELF (this
-// won't be hard), but we haven't done so yet!
//
//===----------------------------------------------------------------------===//
-#include "llvm/CodeGen/ELFWriter.h"
+#define DEBUG_TYPE "elfwriter"
+
+#include "ELFWriter.h"
+#include "ELFCodeEmitter.h"
+#include "ELF.h"
+#include "llvm/Constants.h"
#include "llvm/Module.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/MachineConstantPool.h"
+#include "llvm/CodeGen/MachineFunctionPass.h"
+#include "llvm/Target/TargetData.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 <list>
using namespace llvm;
-//===----------------------------------------------------------------------===//
-// ELFCodeEmitter Implementation
-//===----------------------------------------------------------------------===//
-
-namespace llvm {
- /// ELFCodeEmitter - This class is used by the ELFWriter to emit the code for
- /// functions to the ELF file.
- class ELFCodeEmitter : public MachineCodeEmitter {
- ELFWriter &EW;
- std::vector<unsigned char> &OutputBuffer;
- size_t FnStart;
- public:
- ELFCodeEmitter(ELFWriter &ew) : EW(ew), OutputBuffer(EW.OutputBuffer) {}
-
- void startFunction(MachineFunction &F);
- void finishFunction(MachineFunction &F);
-
- void emitConstantPool(MachineConstantPool *MCP) {
- if (MCP->isEmpty()) return;
- assert(0 && "unimp");
- }
- virtual void emitByte(unsigned char B) {
- OutputBuffer.push_back(B);
- }
- virtual void emitWordAt(unsigned W, unsigned *Ptr) {
- assert(0 && "ni");
- }
- virtual void emitWord(unsigned W) {
- assert(0 && "ni");
- }
- virtual uint64_t getCurrentPCValue() {
- return OutputBuffer.size();
- }
- virtual uint64_t getCurrentPCOffset() {
- return OutputBuffer.size()-FnStart;
- }
- void addRelocation(const MachineRelocation &MR) {
- assert(0 && "relo not handled yet!");
- }
- virtual uint64_t getConstantPoolEntryAddress(unsigned Index) {
- assert(0 && "CP not implementated yet!");
- return 0;
- }
-
- /// JIT SPECIFIC FUNCTIONS - DO NOT IMPLEMENT THESE HERE!
- void startFunctionStub(unsigned StubSize) {
- assert(0 && "JIT specific function called!");
- abort();
- }
- void *finishFunctionStub(const Function *F) {
- assert(0 && "JIT specific function called!");
- abort();
- return 0;
- }
- };
-}
-
-/// startFunction - This callback is invoked when a new machine function is
-/// about to be emitted.
-void ELFCodeEmitter::startFunction(MachineFunction &F) {
- // Align the output buffer to the appropriate alignment.
- unsigned Align = 16; // FIXME: GENERICIZE!!
- ELFWriter::ELFSection &TextSection = EW.SectionList.back();
-
- // Upgrade the section alignment if required.
- if (TextSection.Align < Align) TextSection.Align = Align;
-
- // Add padding zeros to the end of the buffer to make sure that the
- // function will start on the correct byte alignment within the section.
- size_t SectionOff = OutputBuffer.size()-TextSection.Offset;
- if (SectionOff & (Align-1)) {
- // Add padding to get alignment to the correct place.
- size_t Pad = Align-(SectionOff & (Align-1));
- OutputBuffer.resize(OutputBuffer.size()+Pad);
- }
-
- FnStart = OutputBuffer.size();
-}
-
-/// finishFunction - This callback is invoked after the function is completely
-/// finished.
-void ELFCodeEmitter::finishFunction(MachineFunction &F) {
- // We now know the size of the function, add a symbol to represent it.
- ELFWriter::ELFSym FnSym(F.getFunction());
-
- // Figure out the binding (linkage) of the symbol.
- switch (F.getFunction()->getLinkage()) {
- default:
- // appending linkage is illegal for functions.
- assert(0 && "Unknown linkage type!");
- case GlobalValue::ExternalLinkage:
- FnSym.SetBind(ELFWriter::ELFSym::STB_GLOBAL);
- break;
- case GlobalValue::LinkOnceLinkage:
- case GlobalValue::WeakLinkage:
- FnSym.SetBind(ELFWriter::ELFSym::STB_WEAK);
- break;
- case GlobalValue::InternalLinkage:
- FnSym.SetBind(ELFWriter::ELFSym::STB_LOCAL);
- break;
- }
-
- FnSym.SetType(ELFWriter::ELFSym::STT_FUNC);
- FnSym.SectionIdx = EW.SectionList.size()-1; // .text section.
- // Value = Offset from start of .text
- FnSym.Value = FnStart - EW.SectionList.back().Offset;
- FnSym.Size = OutputBuffer.size()-FnStart;
-
- // Finally, add it to the symtab.
- EW.SymbolTable.push_back(FnSym);
+char ELFWriter::ID = 0;
+/// AddELFWriter - Concrete function to add the ELF writer to the function pass
+/// manager.
+MachineCodeEmitter *llvm::AddELFWriter(PassManagerBase &PM,
+ raw_ostream &O,
+ TargetMachine &TM) {
+ ELFWriter *EW = new ELFWriter(O, TM);
+ PM.add(EW);
+ return &EW->getMachineCodeEmitter();
}
//===----------------------------------------------------------------------===//
// ELFWriter Implementation
//===----------------------------------------------------------------------===//
-ELFWriter::ELFWriter(std::ostream &o, TargetMachine &tm) : O(o), TM(tm) {
- e_machine = 0; // e_machine defaults to 'No Machine'
- e_flags = 0; // e_flags defaults to 0, no flags.
+ELFWriter::ELFWriter(raw_ostream &o, TargetMachine &tm)
+ : MachineFunctionPass(&ID), O(o), TM(tm),
+ is64Bit(TM.getTargetData()->getPointerSizeInBits() == 64),
+ isLittleEndian(TM.getTargetData()->isLittleEndian()),
+ ElfHdr(isLittleEndian, is64Bit) {
- is64Bit = TM.getTargetData().getPointerSizeInBits() == 64;
- isLittleEndian = TM.getTargetData().isLittleEndian();
+ TAI = TM.getTargetAsmInfo();
+ TEW = TM.getELFWriterInfo();
// Create the machine code emitter object for this target.
MCE = new ELFCodeEmitter(*this);
+
+ // Inital number of sections
+ NumSections = 0;
}
ELFWriter::~ELFWriter() {
bool ELFWriter::doInitialization(Module &M) {
Mang = new Mangler(M);
- outbyte(0x7F); // EI_MAG0
- outbyte('E'); // EI_MAG1
- outbyte('L'); // EI_MAG2
- outbyte('F'); // EI_MAG3
- outbyte(is64Bit ? 2 : 1); // EI_CLASS
- outbyte(isLittleEndian ? 1 : 2); // EI_DATA
- outbyte(1); // EI_VERSION
- for (unsigned i = OutputBuffer.size(); i != 16; ++i)
- outbyte(0); // EI_PAD up to 16 bytes.
-
- // This should change for shared objects.
- outhalf(1); // e_type = ET_REL
- outhalf(e_machine); // e_machine = whatever the target wants
- outword(1); // e_version = 1
- outaddr(0); // e_entry = 0 -> no entry point in .o file
- outaddr(0); // e_phoff = 0 -> no program header for .o
-
- ELFHeader_e_shoff_Offset = OutputBuffer.size();
- outaddr(0); // e_shoff
- outword(e_flags); // e_flags = whatever the target wants
-
- outhalf(is64Bit ? 64 : 52); // e_ehsize = ELF header size
- outhalf(0); // e_phentsize = prog header entry size
- outhalf(0); // e_phnum = # prog header entries = 0
- outhalf(is64Bit ? 64 : 40); // e_shentsize = sect header entry size
-
-
- ELFHeader_e_shnum_Offset = OutputBuffer.size();
- outhalf(0); // e_shnum = # of section header ents
- ELFHeader_e_shstrndx_Offset = OutputBuffer.size();
- outhalf(0); // e_shstrndx = Section # of '.shstrtab'
-
- // Add the null section.
- SectionList.push_back(ELFSection());
-
- // Start up the symbol table. The first entry in the symtab is the null
+ // ELF Header
+ // ----------
+ // Fields e_shnum e_shstrndx are only known after all section have
+ // been emitted. They locations in the ouput buffer are recorded so
+ // to be patched up later.
+ //
+ // Note
+ // ----
+ // emitWord method behaves differently for ELF32 and ELF64, writing
+ // 4 bytes in the former and 8 in the last for *_off and *_addr elf types
+
+ ElfHdr.emitByte(0x7f); // e_ident[EI_MAG0]
+ ElfHdr.emitByte('E'); // e_ident[EI_MAG1]
+ ElfHdr.emitByte('L'); // e_ident[EI_MAG2]
+ ElfHdr.emitByte('F'); // e_ident[EI_MAG3]
+
+ 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.emitAlignment(16); // e_ident[EI_NIDENT-EI_PAD]
+
+ ElfHdr.emitWord16(ET_REL); // e_type
+ ElfHdr.emitWord16(TEW->getEMachine()); // e_machine = target
+ ElfHdr.emitWord32(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();
+ ElfHdr.emitWord(0); // e_shoff = sec hdr table off in bytes
+ ElfHdr.emitWord32(TEW->getEFlags()); // e_flags = whatever the target wants
+ ElfHdr.emitWord16(TEW->getHdrSize()); // e_ehsize = ELF header size
+ ElfHdr.emitWord16(0); // e_phentsize = prog header entry size
+ ElfHdr.emitWord16(0); // e_phnum = # prog header entries = 0
+
+ // e_shentsize = Section header entry size
+ ElfHdr.emitWord16(TEW->getSHdrSize());
+
+ // e_shnum = # of section header ents
+ ELFHdr_e_shnum_Offset = ElfHdr.size();
+ ElfHdr.emitWord16(0); // Placeholder
+
+ // e_shstrndx = Section # of '.shstrtab'
+ ELFHdr_e_shstrndx_Offset = ElfHdr.size();
+ ElfHdr.emitWord16(0); // Placeholder
+
+ // Add the null section, which is required to be first in the file.
+ getSection("", ELFSection::SHT_NULL, 0);
+
+ // Start up the symbol table. The first entry in the symtab is the null
// entry.
- SymbolTable.push_back(ELFSym(0));
-
- SectionList.push_back(ELFSection(".text", OutputBuffer.size()));
+ SymbolList.push_back(ELFSym(0));
return false;
}
-void ELFWriter::EmitGlobal(GlobalVariable *GV, ELFSection &DataSection,
- ELFSection &BSSSection) {
+void ELFWriter::EmitGlobal(GlobalVariable *GV) {
+
+ // XXX: put local symbols *before* global ones!
+ const Section *S = TAI->SectionForGlobal(GV);
+ DOUT << "Section " << S->getName() << " for global " << GV->getName() << "\n";
+
// If this is an external global, emit it now. TODO: Note that it would be
// better to ignore the symbol here and only add it to the symbol table if
// referenced.
ExternalSym.SetBind(ELFSym::STB_GLOBAL);
ExternalSym.SetType(ELFSym::STT_NOTYPE);
ExternalSym.SectionIdx = ELFSection::SHN_UNDEF;
- SymbolTable.push_back(ExternalSym);
+ SymbolList.push_back(ExternalSym);
return;
}
-
- const Type *GVType = (const Type*)GV->getType();
- unsigned Align = TM.getTargetData().getTypeAlignment(GVType);
- unsigned Size = TM.getTargetData().getTypeSize(GVType);
-
- // If this global has a zero initializer, it is part of the .bss or common
- // section.
- if (GV->getInitializer()->isNullValue()) {
+
+ const TargetData *TD = TM.getTargetData();
+ unsigned Align = TD->getPreferredAlignment(GV);
+ Constant *CV = GV->getInitializer();
+ unsigned Size = TD->getTypeAllocSize(CV->getType());
+
+ // If this global has a zero initializer, go to .bss or common section.
+ if (CV->isNullValue() || isa<UndefValue>(CV)) {
// If this global is part of the common block, add it now. Variables are
// part of the common block if they are zero initialized and allowed to be
// merged with other symbols.
- if (GV->hasLinkOnceLinkage() || GV->hasWeakLinkage()) {
+ if (GV->hasLinkOnceLinkage() || GV->hasWeakLinkage() ||
+ GV->hasCommonLinkage()) {
ELFSym CommonSym(GV);
// Value for common symbols is the alignment required.
CommonSym.Value = Align;
CommonSym.Size = Size;
CommonSym.SetBind(ELFSym::STB_GLOBAL);
CommonSym.SetType(ELFSym::STT_OBJECT);
- // TODO SOMEDAY: add ELF visibility.
CommonSym.SectionIdx = ELFSection::SHN_COMMON;
- SymbolTable.push_back(CommonSym);
+ SymbolList.push_back(CommonSym);
+ getSection(S->getName(), ELFSection::SHT_NOBITS,
+ ELFSection::SHF_WRITE | ELFSection::SHF_ALLOC, 1);
return;
}
// Otherwise, this symbol is part of the .bss section. Emit it now.
-
// Handle alignment. Ensure section is aligned at least as much as required
// by this symbol.
+ ELFSection &BSSSection = getBSSSection();
BSSSection.Align = std::max(BSSSection.Align, Align);
// Within the section, emit enough virtual padding to get us to an alignment
BSSSym.SetType(ELFSym::STT_OBJECT);
switch (GV->getLinkage()) {
- default: // weak/linkonce handled above
+ default: // weak/linkonce/common handled above
assert(0 && "Unexpected linkage type!");
case GlobalValue::AppendingLinkage: // FIXME: This should be improved!
case GlobalValue::ExternalLinkage:
}
// Set the idx of the .bss section
- BSSSym.SectionIdx = &BSSSection-&SectionList[0];
- SymbolTable.push_back(BSSSym);
+ BSSSym.SectionIdx = BSSSection.SectionIdx;
+ if (!GV->hasPrivateLinkage())
+ SymbolList.push_back(BSSSym);
// Reserve space in the .bss section for this symbol.
BSSSection.Size += Size;
return;
}
- // FIXME: handle .rodata
- //assert(!GV->isConstant() && "unimp");
+ /// Emit the Global symbol to the right ELF section
+ ELFSym GblSym(GV);
+ GblSym.Size = Size;
+ GblSym.SetType(ELFSym::STT_OBJECT);
+ GblSym.SetBind(ELFSym::STB_GLOBAL);
+ unsigned Flags = S->getFlags();
+ unsigned SectType = ELFSection::SHT_PROGBITS;
+ unsigned SHdrFlags = ELFSection::SHF_ALLOC;
+
+ if (Flags & SectionFlags::Code)
+ SHdrFlags |= ELFSection::SHF_EXECINSTR;
+ if (Flags & SectionFlags::Writeable)
+ SHdrFlags |= ELFSection::SHF_WRITE;
+ if (Flags & SectionFlags::Mergeable)
+ SHdrFlags |= ELFSection::SHF_MERGE;
+ if (Flags & SectionFlags::TLS)
+ SHdrFlags |= ELFSection::SHF_TLS;
+ if (Flags & SectionFlags::Strings)
+ SHdrFlags |= ELFSection::SHF_STRINGS;
+
+ // Remove tab from section name prefix
+ std::string SectionName(S->getName());
+ size_t Pos = SectionName.find("\t");
+ if (Pos != std::string::npos)
+ SectionName.erase(Pos, 1);
+
+ // The section alignment should be bound to the element with
+ // the largest alignment
+ ELFSection &ElfS = getSection(SectionName, SectType, SHdrFlags);
+ GblSym.SectionIdx = ElfS.SectionIdx;
+ if (Align > ElfS.Align)
+ ElfS.Align = Align;
+
+ // S.Value should contain the symbol index inside the section,
+ // and all symbols should start on their required alignment boundary
+ GblSym.Value = (ElfS.size() + (Align-1)) & (-Align);
+ ElfS.emitAlignment(Align);
+
+ // Emit the constant symbol to its section
+ EmitGlobalConstant(CV, ElfS);
+ SymbolList.push_back(GblSym);
+}
+
+void ELFWriter::EmitGlobalConstantStruct(const ConstantStruct *CVS,
+ ELFSection &GblS) {
+
+ // Print the fields in successive locations. Pad to align if needed!
+ const TargetData *TD = TM.getTargetData();
+ unsigned Size = TD->getTypeAllocSize(CVS->getType());
+ const StructLayout *cvsLayout = TD->getStructLayout(CVS->getType());
+ uint64_t sizeSoFar = 0;
+ for (unsigned i = 0, e = CVS->getNumOperands(); i != e; ++i) {
+ const Constant* field = CVS->getOperand(i);
+
+ // Check if padding is needed and insert one or more 0s.
+ uint64_t fieldSize = TD->getTypeAllocSize(field->getType());
+ uint64_t padSize = ((i == e-1 ? Size : cvsLayout->getElementOffset(i+1))
+ - cvsLayout->getElementOffset(i)) - fieldSize;
+ sizeSoFar += fieldSize + padSize;
+
+ // Now print the actual field value.
+ EmitGlobalConstant(field, GblS);
+
+ // 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);
+ }
+ assert(sizeSoFar == cvsLayout->getSizeInBytes() &&
+ "Layout of constant struct may be incorrect!");
+}
- // FIXME: handle .data
- //assert(0 && "unimp");
+void ELFWriter::EmitGlobalConstant(const Constant *CV, ELFSection &GblS) {
+ const TargetData *TD = TM.getTargetData();
+ unsigned Size = TD->getTypeAllocSize(CV->getType());
+
+ if (const ConstantArray *CVA = dyn_cast<ConstantArray>(CV)) {
+ if (CVA->isString()) {
+ std::string GblStr = CVA->getAsString();
+ 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);
+ }
+ 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) {
+ assert(0 && "X86_FP80Ty global emission not implemented");
+ } else if (CFP->getType() == Type::PPC_FP128Ty)
+ assert(0 && "PPC_FP128Ty global emission not implemented");
+ return;
+ } else if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV)) {
+ if (Size == 4)
+ GblS.emitWord32(CI->getZExtValue());
+ else if (Size == 8)
+ GblS.emitWord64(CI->getZExtValue());
+ else
+ assert(0 && "LargeInt global emission not implemented");
+ 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;
+ }
+ assert(0 && "unknown global constant");
}
/// doFinalization - Now that the module has been completely processed, emit
/// the ELF file to 'O'.
bool ELFWriter::doFinalization(Module &M) {
- // Okay, the .text section has now been finalized. If it contains nothing, do
- // not emit it.
- uint64_t TextSize = OutputBuffer.size() - SectionList.back().Offset;
- if (TextSize == 0) {
- SectionList.pop_back();
- } else {
- ELFSection &Text = SectionList.back();
- Text.Size = TextSize;
- Text.Type = ELFSection::SHT_PROGBITS;
- Text.Flags = ELFSection::SHF_EXECINSTR | ELFSection::SHF_ALLOC;
+ /// FIXME: This should be removed when moving to ObjectCodeEmiter. Since the
+ /// current ELFCodeEmiter uses CurrBuff, ... it doesn't update S.Data
+ /// vector size for .text sections, so this is a quick dirty fix
+ ELFSection &TS = getTextSection();
+ if (TS.Size) {
+ BinaryData &BD = TS.getData();
+ for (unsigned e=0; e<TS.Size; ++e)
+ BD.push_back(BD[e]);
}
- // Okay, the ELF header and .text sections have been completed, build the
- // .data, .bss, and "common" sections next.
- SectionList.push_back(ELFSection(".data", OutputBuffer.size()));
- SectionList.push_back(ELFSection(".bss"));
- ELFSection &DataSection = *(SectionList.end()-2);
- ELFSection &BSSSection = SectionList.back();
+ // Emit .data section placeholder
+ getDataSection();
+
+ // Emit .bss section placeholder
+ getBSSSection();
+
+ // Build and emit data, bss and "common" sections.
for (Module::global_iterator I = M.global_begin(), E = M.global_end();
I != E; ++I)
- EmitGlobal(I, DataSection, BSSSection);
+ EmitGlobal(I);
- // Finish up the data section.
- DataSection.Type = ELFSection::SHT_PROGBITS;
- DataSection.Flags = ELFSection::SHF_WRITE | ELFSection::SHF_ALLOC;
-
- // The BSS Section logically starts at the end of the Data Section (adjusted
- // to the required alignment of the BSSSection).
- BSSSection.Offset = DataSection.Offset+DataSection.Size;
- BSSSection.Type = ELFSection::SHT_NOBITS;
- BSSSection.Flags = ELFSection::SHF_WRITE | ELFSection::SHF_ALLOC;
- if (BSSSection.Align)
- BSSSection.Offset = (BSSSection.Offset+BSSSection.Align-1) &
- ~(BSSSection.Align-1);
+ // Emit non-executable stack note
+ if (TAI->getNonexecutableStackDirective())
+ getNonExecStackSection();
// Emit the symbol table now, if non-empty.
EmitSymbolTable();
- // FIXME: Emit the relocations now.
+ // Emit the relocation sections.
+ EmitRelocations();
- // Emit the string table for the sections in the ELF file we have.
+ // Emit the sections string table.
EmitSectionTableStringTable();
- // Emit the .o file section table.
- EmitSectionTable();
-
- // Emit the .o file to the specified stream.
- O.write((char*)&OutputBuffer[0], OutputBuffer.size());
+ // Dump the sections and section table to the .o file.
+ OutputSectionsAndSectionTable();
- // Free the output buffer.
- std::vector<unsigned char>().swap(OutputBuffer);
+ // We are done with the abstract symbols.
+ SectionList.clear();
+ NumSections = 0;
// Release the name mangler object.
delete Mang; Mang = 0;
return false;
}
+/// EmitRelocations - Emit relocations
+void ELFWriter::EmitRelocations() {
+}
+
+/// EmitSymbol - Write symbol 'Sym' to the symbol table 'SymbolTable'
+void ELFWriter::EmitSymbol(BinaryObject &SymbolTable, ELFSym &Sym) {
+ if (is64Bit) {
+ SymbolTable.emitWord32(Sym.NameIdx);
+ SymbolTable.emitByte(Sym.Info);
+ SymbolTable.emitByte(Sym.Other);
+ SymbolTable.emitWord16(Sym.SectionIdx);
+ SymbolTable.emitWord64(Sym.Value);
+ SymbolTable.emitWord64(Sym.Size);
+ } else {
+ SymbolTable.emitWord32(Sym.NameIdx);
+ SymbolTable.emitWord32(Sym.Value);
+ SymbolTable.emitWord32(Sym.Size);
+ SymbolTable.emitByte(Sym.Info);
+ SymbolTable.emitByte(Sym.Other);
+ SymbolTable.emitWord16(Sym.SectionIdx);
+ }
+}
+
+/// EmitSectionHeader - Write section 'Section' header in 'SHdrTab'
+/// Section Header Table
+void ELFWriter::EmitSectionHeader(BinaryObject &SHdrTab,
+ const ELFSection &SHdr) {
+ SHdrTab.emitWord32(SHdr.NameIdx);
+ SHdrTab.emitWord32(SHdr.Type);
+ if (is64Bit) {
+ SHdrTab.emitWord64(SHdr.Flags);
+ SHdrTab.emitWord(SHdr.Addr);
+ SHdrTab.emitWord(SHdr.Offset);
+ SHdrTab.emitWord64(SHdr.Size);
+ SHdrTab.emitWord32(SHdr.Link);
+ SHdrTab.emitWord32(SHdr.Info);
+ SHdrTab.emitWord64(SHdr.Align);
+ SHdrTab.emitWord64(SHdr.EntSize);
+ } else {
+ SHdrTab.emitWord32(SHdr.Flags);
+ SHdrTab.emitWord(SHdr.Addr);
+ SHdrTab.emitWord(SHdr.Offset);
+ SHdrTab.emitWord32(SHdr.Size);
+ SHdrTab.emitWord32(SHdr.Link);
+ SHdrTab.emitWord32(SHdr.Info);
+ SHdrTab.emitWord32(SHdr.Align);
+ SHdrTab.emitWord32(SHdr.EntSize);
+ }
+}
+
/// EmitSymbolTable - If the current symbol table is non-empty, emit the string
/// table for it and then the symbol table itself.
void ELFWriter::EmitSymbolTable() {
- if (SymbolTable.size() == 1) return; // Only the null entry.
+ if (SymbolList.size() == 1) return; // Only the null entry.
// FIXME: compact all local symbols to the start of the symtab.
unsigned FirstNonLocalSymbol = 1;
- SectionList.push_back(ELFSection(".strtab", OutputBuffer.size()));
- ELFSection &StrTab = SectionList.back();
- StrTab.Type = ELFSection::SHT_STRTAB;
- StrTab.Align = 1;
+ ELFSection &StrTab = getStringTableSection();
// Set the zero'th symbol to a null byte, as required.
- outbyte(0);
- SymbolTable[0].NameIdx = 0;
+ StrTab.emitByte(0);
+
unsigned Index = 1;
- for (unsigned i = 1, e = SymbolTable.size(); i != e; ++i) {
+ for (unsigned i = 1, e = SymbolList.size(); i != e; ++i) {
// Use the name mangler to uniquify the LLVM symbol.
- std::string Name = Mang->getValueName(SymbolTable[i].GV);
+ std::string Name = Mang->getValueName(SymbolList[i].GV);
if (Name.empty()) {
- SymbolTable[i].NameIdx = 0;
+ SymbolList[i].NameIdx = 0;
} else {
- SymbolTable[i].NameIdx = Index;
-
- // Add the name to the output buffer, including the null terminator.
- OutputBuffer.insert(OutputBuffer.end(), Name.begin(), Name.end());
-
- // Add a null terminator.
- OutputBuffer.push_back(0);
+ SymbolList[i].NameIdx = Index;
+ StrTab.emitString(Name);
// Keep track of the number of bytes emitted to this section.
Index += Name.size()+1;
}
}
-
- StrTab.Size = OutputBuffer.size()-StrTab.Offset;
+ assert(Index == StrTab.size());
+ StrTab.Size = Index;
// Now that we have emitted the string table and know the offset into the
// string table of each symbol, emit the symbol table itself.
- align(is64Bit ? 8 : 4);
-
- SectionList.push_back(ELFSection(".symtab", OutputBuffer.size()));
- ELFSection &SymTab = SectionList.back();
- SymTab.Type = ELFSection::SHT_SYMTAB;
- SymTab.Align = is64Bit ? 8 : 4;
- SymTab.Link = SectionList.size()-2; // Section Index of .strtab.
- SymTab.Info = FirstNonLocalSymbol; // First non-STB_LOCAL symbol.
- SymTab.EntSize = 16; // Size of each symtab entry. FIXME: wrong for ELF64
-
- if (!is64Bit) { // 32-bit and 64-bit formats are shuffled a bit.
- for (unsigned i = 0, e = SymbolTable.size(); i != e; ++i) {
- ELFSym &Sym = SymbolTable[i];
- outword(Sym.NameIdx);
- outaddr32(Sym.Value);
- outword(Sym.Size);
- outbyte(Sym.Info);
- outbyte(Sym.Other);
- outhalf(Sym.SectionIdx);
- }
- } else {
- for (unsigned i = 0, e = SymbolTable.size(); i != e; ++i) {
- ELFSym &Sym = SymbolTable[i];
- outword(Sym.NameIdx);
- outbyte(Sym.Info);
- outbyte(Sym.Other);
- outhalf(Sym.SectionIdx);
- outaddr64(Sym.Value);
- outxword(Sym.Size);
- }
- }
+ ELFSection &SymTab = getSymbolTableSection();
+ SymTab.Align = TEW->getSymTabAlignment();
+ SymTab.Link = StrTab.SectionIdx; // Section Index of .strtab.
+ SymTab.Info = FirstNonLocalSymbol; // First non-STB_LOCAL symbol.
+
+ // Size of each symtab entry.
+ SymTab.EntSize = TEW->getSymTabEntrySize();
+
+ for (unsigned i = 0, e = SymbolList.size(); i != e; ++i)
+ EmitSymbol(SymTab, SymbolList[i]);
- SymTab.Size = OutputBuffer.size()-SymTab.Offset;
+ SymTab.Size = SymTab.size();
}
/// EmitSectionTableStringTable - This method adds and emits a section for the
/// section names.
void ELFWriter::EmitSectionTableStringTable() {
// First step: add the section for the string table to the list of sections:
- SectionList.push_back(ELFSection(".shstrtab", OutputBuffer.size()));
- SectionList.back().Type = ELFSection::SHT_STRTAB;
+ ELFSection &SHStrTab = getSection(".shstrtab", ELFSection::SHT_STRTAB, 0);
// Now that we know which section number is the .shstrtab section, update the
// e_shstrndx entry in the ELF header.
- fixhalf(SectionList.size()-1, ELFHeader_e_shstrndx_Offset);
+ ElfHdr.fixWord16(SHStrTab.SectionIdx, ELFHdr_e_shstrndx_Offset);
// Set the NameIdx of each section in the string table and emit the bytes for
// the string table.
unsigned Index = 0;
- for (unsigned i = 0, e = SectionList.size(); i != e; ++i) {
+ for (std::list<ELFSection>::iterator I = SectionList.begin(),
+ E = SectionList.end(); I != E; ++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.
- SectionList[i].NameIdx = Index;
-
- // Add the name to the output buffer, including the null terminator.
- OutputBuffer.insert(OutputBuffer.end(), SectionList[i].Name.begin(),
- SectionList[i].Name.end());
- // Add a null terminator.
- OutputBuffer.push_back(0);
+ I->NameIdx = Index;
+ SHStrTab.emitString(I->getName());
// Keep track of the number of bytes emitted to this section.
- Index += SectionList[i].Name.size()+1;
+ Index += I->getName().size()+1;
}
// Set the size of .shstrtab now that we know what it is.
- SectionList.back().Size = Index;
+ assert(Index == SHStrTab.size());
+ SHStrTab.Size = Index;
}
-/// EmitSectionTable - Now that we have emitted the entire contents of the file
-/// (all of the sections), emit the section table which informs the reader where
-/// the boundaries are.
-void ELFWriter::EmitSectionTable() {
- // Now that all of the sections have been emitted, set the e_shnum entry in
- // the ELF header.
- fixhalf(SectionList.size(), ELFHeader_e_shnum_Offset);
-
- // Now that we know the offset in the file of the section table (which we emit
- // next), update the e_shoff address in the ELF header.
- fixaddr(OutputBuffer.size(), ELFHeader_e_shoff_Offset);
-
- // Emit all of the section table entries.
- for (unsigned i = 0, e = SectionList.size(); i != e; ++i) {
- const ELFSection &S = SectionList[i];
- outword(S.NameIdx); // sh_name - Symbol table name idx
- outword(S.Type); // sh_type - Section contents & semantics
- outword(S.Flags); // sh_flags - Section flags.
- outaddr(S.Addr); // sh_addr - The mem address this section appears in.
- outaddr(S.Offset); // sh_offset - The offset from the start of the file.
- outword(S.Size); // sh_size - The section size.
- outword(S.Link); // sh_link - Section header table index link.
- outword(S.Info); // sh_info - Auxillary information.
- outword(S.Align); // sh_addralign - Alignment of section.
- outword(S.EntSize); // sh_entsize - Size of each entry in the section.
+/// OutputSectionsAndSectionTable - Now that we have constructed the file header
+/// and all of the sections, emit these to the ostream destination and emit the
+/// SectionTable.
+void ELFWriter::OutputSectionsAndSectionTable() {
+ // 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;
+ continue;
+ }
+
+ // Update Section size
+ if (!I->Size)
+ I->Size = I->size();
+
+ // Align FileOff to whatever the alignment restrictions of the section are.
+ if (I->Align)
+ FileOff = (FileOff+I->Align-1) & ~(I->Align-1);
+
+ I->Offset = FileOff;
+ FileOff += I->Size;
+ }
+
+ // Align Section Header.
+ unsigned TableAlign = is64Bit ? 8 : 4;
+ FileOff = (FileOff+TableAlign-1) & ~(TableAlign-1);
+
+ // Now that we know where all of the sections will be emitted, set the e_shnum
+ // entry in the ELF header.
+ ElfHdr.fixWord16(NumSections, ELFHdr_e_shnum_Offset);
+
+ // Now that we know the offset in the file of the section table, update the
+ // e_shoff address in the ELF header.
+ ElfHdr.fixWord(FileOff, ELFHdr_e_shoff_Offset);
+
+ // Now that we know all of the data in the file header, emit it and all of the
+ // sections!
+ O.write((char *)&ElfHdr.getData()[0], ElfHdr.size());
+ FileOff = ElfHdr.size();
+
+ // Section Header Table blob
+ 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";
+
+ // Align FileOff to whatever the alignment restrictions of the section are.
+ if (S.Align) {
+ for (size_t NewFileOff = (FileOff+S.Align-1) & ~(S.Align-1);
+ FileOff != NewFileOff; ++FileOff)
+ O << (char)0xAB;
+ }
+
+ if (S.size()) {
+ O.write((char *)&S.getData()[0], S.Size);
+ FileOff += S.Size;
+ }
+
+ EmitSectionHeader(SHdrTable, S);
+ SectionList.pop_front();
}
- // Release the memory allocated for the section list.
- std::vector<ELFSection>().swap(SectionList);
+ // Align output for the section table.
+ for (size_t NewFileOff = (FileOff+TableAlign-1) & ~(TableAlign-1);
+ FileOff != NewFileOff; ++FileOff)
+ O << (char)0xAB;
+
+ // Emit the section table itself.
+ O.write((char *)&SHdrTable.getData()[0], SHdrTable.size());
}
projects / oota-llvm.git / blobdiff