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Support for ELF Visibility

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Emission for globals, using the correct data sections
Function alignment can be computed for each target using TargetELFWriterInfo
Some small fixes



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73201 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Bruno Cardoso Lopes 2009-06-11 19:16:03 +00:00
parent 3590abfda0
commit c997d45ae5
8 changed files with 337 additions and 99 deletions
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19
include/llvm/Target/TargetELFWriterInfo.h
View File

@ -14,6 +14,10 @@
#ifndef LLVM_TARGET_TARGETELFWRITERINFO_H
#define LLVM_TARGET_TARGETELFWRITERINFO_H
#include "llvm/Target/TargetData.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/Function.h"
namespace llvm {
//===--------------------------------------------------------------------===//
@ -21,9 +25,11 @@ namespace llvm {
//===--------------------------------------------------------------------===//
class TargetELFWriterInfo {
protected:
// EMachine - This field is the target specific value to emit as the
// e_machine member of the ELF header.
unsigned short EMachine;
TargetMachine &TM;
public:
// Machine architectures
@ -44,10 +50,21 @@ namespace llvm {
EM_X86_64 = 62 // AMD64
};
explicit TargetELFWriterInfo(MachineType machine) : EMachine(machine) {}
explicit TargetELFWriterInfo(TargetMachine &tm) : TM(tm) {}
virtual ~TargetELFWriterInfo() {}
unsigned short getEMachine() const { return EMachine; }
/// getFunctionAlignment - Returns the alignment for function 'F', targets
/// with different alignment constraints should overload this method
virtual unsigned getFunctionAlignment(const Function *F) const {
const TargetData *TD = TM.getTargetData();
unsigned FnAlign = F->getAlignment();
unsigned TDAlign = TD->getPointerABIAlignment();
unsigned Align = std::max(FnAlign, TDAlign);
assert(!(Align & (Align-1)) && "Alignment is not a power of two!");
return Align;
}
};
} // end llvm namespace

55
lib/CodeGen/ELF.h
View File

@ -21,12 +21,12 @@
#ifndef CODEGEN_ELF_H
#define CODEGEN_ELF_H
#include "llvm/GlobalVariable.h"
#include "llvm/CodeGen/MachineRelocation.h"
#include "llvm/Support/DataTypes.h"
#include <cstring>
namespace llvm {
class GlobalVariable;
// Identification Indexes
enum {
@ -100,18 +100,20 @@ namespace llvm {
/// table at the end of the file.
struct ELFSection {
// Name of the section
std::string Name;
// ELF specific fields
std::string Name; // Name of the section.
unsigned NameIdx; // Index in .shstrtab of name, once emitted.
unsigned Type;
unsigned Flags;
uint64_t Addr;
unsigned Offset;
unsigned Size;
unsigned Link;
unsigned Info;
unsigned Align;
unsigned EntSize;
unsigned NameIdx; // sh_name - .shstrtab idx of name, once emitted.
unsigned Type; // sh_type - Section contents & semantics
unsigned Flags; // sh_flags - Section flags.
uint64_t Addr; // sh_addr - The mem addr this section is in.
unsigned Offset; // sh_offset - Offset from the file start
unsigned Size; // sh_size - The section size.
unsigned Link; // sh_link - Section header table index link.
unsigned Info; // sh_info - Auxillary information.
unsigned Align; // sh_addralign - Alignment of section.
unsigned EntSize; // sh_entsize - Size of entries in the section e
// Section Header Flags
enum {
@ -207,9 +209,33 @@ namespace llvm {
STT_FILE = 4
};
enum {
STV_DEFAULT = 0, // Visibility is specified by binding type
STV_INTERNAL = 1, // Defined by processor supplements
STV_HIDDEN = 2, // Not visible to other components
STV_PROTECTED = 3 // Visible in other components but not preemptable
};
ELFSym(const GlobalValue *gv) : GV(gv), NameIdx(0), Value(0),
Size(0), Info(0), Other(0),
SectionIdx(ELFSection::SHN_UNDEF) {}
SectionIdx(ELFSection::SHN_UNDEF) {
if (!GV)
return;
switch (GV->getVisibility()) {
default:
assert(0 && "unknown visibility type");
case GlobalValue::DefaultVisibility:
Other = STV_DEFAULT;
break;
case GlobalValue::HiddenVisibility:
Other = STV_HIDDEN;
break;
case GlobalValue::ProtectedVisibility:
Other = STV_PROTECTED;
break;
}
}
void SetBind(unsigned X) {
assert(X == (X & 0xF) && "Bind value out of range!");
@ -219,6 +245,9 @@ namespace llvm {
assert(X == (X & 0xF) && "Type value out of range!");
Info = (Info & 0xF0) | X;
}
static unsigned getEntrySize(bool is64Bit)
{ return is64Bit ? 24 : 16; }
};
} // end namespace llvm

19
lib/CodeGen/ELFCodeEmitter.cpp
View File

@ -15,7 +15,6 @@
#include "llvm/Function.h"
#include "llvm/CodeGen/MachineConstantPool.h"
#include "llvm/CodeGen/MachineJumpTableInfo.h"
#include "llvm/Target/TargetData.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/Support/Debug.h"
@ -28,27 +27,21 @@ namespace llvm {
/// startFunction - This callback is invoked when a new machine function is
/// about to be emitted.
void ELFCodeEmitter::startFunction(MachineFunction &MF) {
const TargetData *TD = TM.getTargetData();
const Function *F = MF.getFunction();
// Align the output buffer to the appropriate alignment, power of 2.
unsigned FnAlign = F->getAlignment();
unsigned TDAlign = TD->getPrefTypeAlignment(F->getType());
unsigned Align = std::max(FnAlign, TDAlign);
assert(!(Align & (Align-1)) && "Alignment is not a power of two!");
// Get the ELF Section that this function belongs in.
ES = &EW.getTextSection();
DOUT << "processing function: " << MF.getFunction()->getName() << "\n";
// FIXME: better memory management, this will be replaced by BinaryObjects
ES->SectionData.reserve(4096);
BufferBegin = &ES->SectionData[0];
BufferEnd = BufferBegin + ES->SectionData.capacity();
// Upgrade the section alignment if required.
// Align the output buffer with function alignment, and
// upgrade the section alignment if required
unsigned Align =
TM.getELFWriterInfo()->getFunctionAlignment(MF.getFunction());
if (ES->Align < Align) ES->Align = Align;
// Round the size up to the correct alignment for starting the new function.
ES->Size = (ES->Size + (Align-1)) & (-Align);
// Snaity check on allocated space for text section

281
lib/CodeGen/ELFWriter.cpp
View File

@ -26,9 +26,6 @@
// ...
// #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!
//
//===----------------------------------------------------------------------===//
#define DEBUG_TYPE "elfwriter"
@ -36,6 +33,7 @@
#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"
@ -44,10 +42,8 @@
#include "llvm/CodeGen/MachineConstantPool.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
#include "llvm/Target/TargetData.h"
#include "llvm/Target/TargetELFWriterInfo.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/Support/Mangler.h"
#include "llvm/Support/OutputBuffer.h"
#include "llvm/Support/Streams.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/Support/Debug.h"
@ -76,6 +72,7 @@ ELFWriter::ELFWriter(raw_ostream &o, TargetMachine &tm)
ElfHdr = new ELFHeader(TM.getELFWriterInfo()->getEMachine(), 0,
is64Bit, isLittleEndian);
TAI = TM.getTargetAsmInfo();
// Create the machine code emitter object for this target.
MCE = new ELFCodeEmitter(*this);
@ -152,6 +149,11 @@ bool ELFWriter::doInitialization(Module &M) {
}
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.
@ -164,13 +166,13 @@ void ELFWriter::EmitGlobal(GlobalVariable *GV) {
return;
}
unsigned Align = TM.getTargetData()->getPreferredAlignment(GV);
unsigned Size =
TM.getTargetData()->getTypeAllocSize(GV->getType()->getElementType());
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, it is part of the .bss or common
// section.
if (GV->getInitializer()->isNullValue()) {
// 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.
@ -182,14 +184,14 @@ void ELFWriter::EmitGlobal(GlobalVariable *GV) {
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);
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();
@ -227,11 +229,124 @@ void ELFWriter::EmitGlobal(GlobalVariable *GV) {
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;
// FIXME: handle .data
//assert(0 && "unimp");
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;
DataBuffer &GblCstBuf = ElfS.SectionData;
OutputBuffer GblCstTab(GblCstBuf, is64Bit, isLittleEndian);
// S.Value should contain the symbol index inside the section,
// and all symbols should start on their required alignment boundary
GblSym.Value = (GblCstBuf.size() + (Align-1)) & (-Align);
GblCstBuf.insert(GblCstBuf.end(), GblSym.Value-GblCstBuf.size(), 0);
// Emit the constant symbol to its section
EmitGlobalConstant(CV, GblCstTab);
SymbolTable.push_back(GblSym);
}
void ELFWriter::EmitGlobalConstantStruct(const ConstantStruct *CVS,
OutputBuffer &GblCstTab) {
// 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, GblCstTab);
// 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++)
GblCstTab.outbyte(0);
}
assert(sizeSoFar == cvsLayout->getSizeInBytes() &&
"Layout of constant struct may be incorrect!");
}
void ELFWriter::EmitGlobalConstant(const Constant *CV, OutputBuffer &GblCstTab) {
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();
GblCstTab.outstring(GblStr, GblStr.length());
} else { // Not a string. Print the values in successive locations
for (unsigned i = 0, e = CVA->getNumOperands(); i != e; ++i)
EmitGlobalConstant(CVA->getOperand(i), GblCstTab);
}
return;
} else if (const ConstantStruct *CVS = dyn_cast<ConstantStruct>(CV)) {
EmitGlobalConstantStruct(CVS, GblCstTab);
return;
} else if (const ConstantFP *CFP = dyn_cast<ConstantFP>(CV)) {
uint64_t Val = CFP->getValueAPF().bitcastToAPInt().getZExtValue();
if (CFP->getType() == Type::DoubleTy)
GblCstTab.outxword(Val);
else if (CFP->getType() == Type::FloatTy)
GblCstTab.outword(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)
GblCstTab.outword(CI->getZExtValue());
else if (Size == 8)
GblCstTab.outxword(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), GblCstTab);
return;
}
assert(0 && "unknown global constant");
}
@ -243,12 +358,27 @@ bool ELFWriter::runOnMachineFunction(MachineFunction &MF) {
/// doFinalization - Now that the module has been completely processed, emit
/// the ELF file to 'O'.
bool ELFWriter::doFinalization(Module &M) {
// Okay, the ELF header and .text sections have been completed, build the
// .data, .bss, and "common" sections next.
/// FIXME: This should be removed when moving to BinaryObjects. Since the
/// current ELFCodeEmiter uses CurrBuff, ... it doesn't update S.SectionData
/// vector size for .text sections, so this is a quick dirty fix
ELFSection &TS = getTextSection();
if (TS.Size)
for (unsigned e=0; e<TS.Size; ++e)
TS.SectionData.push_back(TS.SectionData[e]);
// Get .data and .bss section, they should always be present in the binary
getDataSection();
getBSSSection();
// build data, bss and "common" sections.
for (Module::global_iterator I = M.global_begin(), E = M.global_end();
I != E; ++I)
EmitGlobal(I);
// Emit non-executable stack note
if (TAI->getNonexecutableStackDirective())
getSection(".note.GNU-stack", ELFSection::SHT_PROGBITS, 0, 1);
// Emit the symbol table now, if non-empty.
EmitSymbolTable();
@ -274,6 +404,51 @@ bool ELFWriter::doFinalization(Module &M) {
void ELFWriter::EmitRelocations() {
}
/// EmitSymbol - Write symbol 'Sym' to the symbol table 'SymTabOut'
void ELFWriter::EmitSymbol(OutputBuffer &SymTabOut, ELFSym &Sym) {
if (is64Bit) {
SymTabOut.outword(Sym.NameIdx);
SymTabOut.outbyte(Sym.Info);
SymTabOut.outbyte(Sym.Other);
SymTabOut.outhalf(Sym.SectionIdx);
SymTabOut.outaddr64(Sym.Value);
SymTabOut.outxword(Sym.Size);
} else {
SymTabOut.outword(Sym.NameIdx);
SymTabOut.outaddr32(Sym.Value);
SymTabOut.outword(Sym.Size);
SymTabOut.outbyte(Sym.Info);
SymTabOut.outbyte(Sym.Other);
SymTabOut.outhalf(Sym.SectionIdx);
}
}
/// EmitSectionHeader - Write section 'Section' header in 'TableOut'
/// Section Header Table
void ELFWriter::EmitSectionHeader(OutputBuffer &TableOut, const ELFSection &S) {
TableOut.outword(S.NameIdx);
TableOut.outword(S.Type);
if (is64Bit) {
TableOut.outxword(S.Flags);
TableOut.outaddr(S.Addr);
TableOut.outaddr(S.Offset);
TableOut.outxword(S.Size);
TableOut.outword(S.Link);
TableOut.outword(S.Info);
TableOut.outxword(S.Align);
TableOut.outxword(S.EntSize);
} else {
TableOut.outword(S.Flags);
TableOut.outaddr(S.Addr);
TableOut.outaddr(S.Offset);
TableOut.outword(S.Size);
TableOut.outword(S.Link);
TableOut.outword(S.Info);
TableOut.outword(S.Align);
TableOut.outword(S.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() {
@ -282,14 +457,13 @@ void ELFWriter::EmitSymbolTable() {
// FIXME: compact all local symbols to the start of the symtab.
unsigned FirstNonLocalSymbol = 1;
ELFSection &StrTab = getSection(".strtab", ELFSection::SHT_STRTAB, 0);
StrTab.Align = 1;
ELFSection &StrTab = getStringTableSection();
DataBuffer &StrTabBuf = StrTab.SectionData;
OutputBuffer StrTabOut(StrTabBuf, is64Bit, isLittleEndian);
// Set the zero'th symbol to a null byte, as required.
StrTabOut.outbyte(0);
unsigned Index = 1;
for (unsigned i = 1, e = SymbolTable.size(); i != e; ++i) {
// Use the name mangler to uniquify the LLVM symbol.
@ -315,35 +489,19 @@ void ELFWriter::EmitSymbolTable() {
// 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 = getSection(".symtab", ELFSection::SHT_SYMTAB, 0);
ELFSection &SymTab = getSymbolTableSection();
SymTab.Align = is64Bit ? 8 : 4;
SymTab.Link = StrTab.SectionIdx; // Section Index of .strtab.
SymTab.Info = FirstNonLocalSymbol; // First non-STB_LOCAL symbol.
SymTab.EntSize = is64Bit ? 24 : 16; // Size of each symtab entry.
// Size of each symtab entry.
SymTab.EntSize = ELFSym::getEntrySize(is64Bit);
DataBuffer &SymTabBuf = SymTab.SectionData;
OutputBuffer SymTabOut(SymTabBuf, is64Bit, isLittleEndian);
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];
SymTabOut.outword(Sym.NameIdx);
SymTabOut.outaddr32(Sym.Value);
SymTabOut.outword(Sym.Size);
SymTabOut.outbyte(Sym.Info);
SymTabOut.outbyte(Sym.Other);
SymTabOut.outhalf(Sym.SectionIdx);
}
} else {
for (unsigned i = 0, e = SymbolTable.size(); i != e; ++i) {
ELFSym &Sym = SymbolTable[i];
SymTabOut.outword(Sym.NameIdx);
SymTabOut.outbyte(Sym.Info);
SymTabOut.outbyte(Sym.Other);
SymTabOut.outhalf(Sym.SectionIdx);
SymTabOut.outaddr64(Sym.Value);
SymTabOut.outxword(Sym.Size);
}
}
for (unsigned i = 0, e = SymbolTable.size(); i != e; ++i)
EmitSymbol(SymTabOut, SymbolTable[i]);
SymTab.Size = SymTabBuf.size();
}
@ -393,7 +551,7 @@ void ELFWriter::OutputSectionsAndSectionTable() {
// Pass #1: Compute the file offset for each section.
size_t FileOff = FileHeader.size(); // File header first.
// Emit all of the section data in order.
// Adjust alignment of all section if needed.
for (std::list<ELFSection>::iterator I = SectionList.begin(),
E = SectionList.end(); I != E; ++I) {
@ -401,6 +559,11 @@ void ELFWriter::OutputSectionsAndSectionTable() {
if (!I->SectionIdx)
continue;
if (!I->SectionData.size()) {
I->Offset = FileOff;
continue;
}
// Update Section size
if (!I->Size)
I->Size = I->SectionData.size();
@ -438,30 +601,24 @@ void ELFWriter::OutputSectionsAndSectionTable() {
// Emit all of the section data and build the section table itself.
while (!SectionList.empty()) {
const ELFSection &S = *SectionList.begin();
DOUT << "SectionIdx: " << S.SectionIdx << ", Name: " << S.Name
<< ", Size: " << S.Size << ", Offset: " << S.Offset
<< ", SectionData Size: " << S.SectionData.size() << "\n";
// Align FileOff to whatever the alignment restrictions of the section are.
if (S.Align)
if (S.Align) {
for (size_t NewFileOff = (FileOff+S.Align-1) & ~(S.Align-1);
FileOff != NewFileOff; ++FileOff)
O << (char)0xAB;
}
if (S.SectionData.size()) {
O.write((char*)&S.SectionData[0], S.Size);
DOUT << "SectionIdx: " << S.SectionIdx << ", Name: " << S.Name
<< ", Size: " << S.Size << ", Offset: " << S.Offset << "\n";
FileOff += S.Size;
}
TableOut.outword(S.NameIdx); // sh_name - Symbol table name idx
TableOut.outword(S.Type); // sh_type - Section contents & semantics
TableOut.outaddr(S.Flags); // sh_flags - Section flags.
TableOut.outaddr(S.Addr); // sh_addr - The mem addr this section is in.
TableOut.outaddr(S.Offset); // sh_offset - Offset from the file start.
TableOut.outaddr(S.Size); // sh_size - The section size.
TableOut.outword(S.Link); // sh_link - Section header table index link.
TableOut.outword(S.Info); // sh_info - Auxillary information.
TableOut.outaddr(S.Align); // sh_addralign - Alignment of section.
TableOut.outaddr(S.EntSize); // sh_entsize - Size of entries in the section
EmitSectionHeader(TableOut, S);
SectionList.pop_front();
}

31
lib/CodeGen/ELFWriter.h
View File

@ -16,15 +16,19 @@
#include "llvm/ADT/SetVector.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
#include "llvm/Support/OutputBuffer.h"
#include "llvm/Target/TargetAsmInfo.h"
#include "llvm/Target/TargetELFWriterInfo.h"
#include "ELF.h"
#include <list>
#include <map>
namespace llvm {
class ConstantStruct;
class ELFCodeEmitter;
class GlobalVariable;
class Mangler;
class MachineCodeEmitter;
class ELFCodeEmitter;
class raw_ostream;
/// ELFWriter - This class implements the common target-independent code for
@ -59,6 +63,10 @@ namespace llvm {
/// code for functions to the .o file.
ELFCodeEmitter *MCE;
/// TAI - Target Asm Info, provide information about section names for
/// globals and other target specific stuff.
const TargetAsmInfo *TAI;
//===------------------------------------------------------------------===//
// Properties inferred automatically from the target machine.
//===------------------------------------------------------------------===//
@ -97,8 +105,8 @@ namespace llvm {
/// getSection - Return the section with the specified name, creating a new
/// section if one does not already exist.
ELFSection &getSection(const std::string &Name,
unsigned Type, unsigned Flags = 0) {
ELFSection &getSection(const std::string &Name, unsigned Type,
unsigned Flags = 0, unsigned Align = 0) {
ELFSection *&SN = SectionLookup[Name];
if (SN) return *SN;
@ -108,6 +116,7 @@ namespace llvm {
SN->Type = Type;
SN->Flags = Flags;
SN->Link = ELFSection::SHN_UNDEF;
SN->Align = Align;
return *SN;
}
@ -116,10 +125,19 @@ namespace llvm {
ELFSection::SHF_EXECINSTR | ELFSection::SHF_ALLOC);
}
ELFSection &getSymbolTableSection() {
return getSection(".symtab", ELFSection::SHT_SYMTAB, 0);
}
ELFSection &getStringTableSection() {
return getSection(".strtab", ELFSection::SHT_STRTAB, 0, 1);
}
ELFSection &getDataSection() {
return getSection(".data", ELFSection::SHT_PROGBITS,
ELFSection::SHF_WRITE | ELFSection::SHF_ALLOC);
}
ELFSection &getBSSSection() {
return getSection(".bss", ELFSection::SHT_NOBITS,
ELFSection::SHF_WRITE | ELFSection::SHF_ALLOC);
@ -144,9 +162,14 @@ namespace llvm {
unsigned ELFHdr_e_shnum_Offset; // e_shnum in ELF header.
private:
void EmitGlobal(GlobalVariable *GV);
void EmitSymbolTable();
void EmitGlobalConstant(const Constant *C, OutputBuffer &GblCstTab);
void EmitGlobalConstantStruct(const ConstantStruct *CVS,
OutputBuffer &GblCstTab);
void EmitRelocations();
void EmitSectionHeader(OutputBuffer &TableOut, const ELFSection &Section);
void EmitSectionTableStringTable();
void EmitSymbol(OutputBuffer &SymTabOut, ELFSym &Sym);
void EmitSymbolTable();
void OutputSectionsAndSectionTable();
};
}

22
lib/Target/X86/X86ELFWriterInfo.cpp
View File

@ -12,8 +12,26 @@
//===----------------------------------------------------------------------===//
#include "X86ELFWriterInfo.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/DerivedTypes.h"
using namespace llvm;
X86ELFWriterInfo::X86ELFWriterInfo(bool is64Bit) :
TargetELFWriterInfo(is64Bit ? EM_X86_64 : EM_386) {}
X86ELFWriterInfo::X86ELFWriterInfo(TargetMachine &TM)
: TargetELFWriterInfo(TM) {
bool is64Bit = TM.getTargetData()->getPointerSizeInBits() == 64;
EMachine = is64Bit ? EM_X86_64 : EM_386;
}
X86ELFWriterInfo::~X86ELFWriterInfo() {}
unsigned X86ELFWriterInfo::getFunctionAlignment(const Function *F) const {
unsigned FnAlign = 4;
if (F->hasFnAttr(Attribute::OptimizeForSize))
FnAlign = 1;
if (F->getAlignment())
FnAlign = Log2_32(F->getAlignment());
return (1 << FnAlign);
}

4
lib/Target/X86/X86ELFWriterInfo.h
View File

@ -20,8 +20,10 @@ namespace llvm {
class X86ELFWriterInfo : public TargetELFWriterInfo {
public:
X86ELFWriterInfo(bool is64Bit);
X86ELFWriterInfo(TargetMachine &TM);
virtual ~X86ELFWriterInfo();
virtual unsigned getFunctionAlignment(const Function *F) const;
};
} // end llvm namespace

3
lib/Target/X86/X86TargetMachine.cpp
View File

@ -133,8 +133,7 @@ X86TargetMachine::X86TargetMachine(const Module &M, const std::string &FS,
DataLayout(Subtarget.getDataLayout()),
FrameInfo(TargetFrameInfo::StackGrowsDown,
Subtarget.getStackAlignment(), Subtarget.is64Bit() ? -8 : -4),
InstrInfo(*this), JITInfo(*this), TLInfo(*this),
ELFWriterInfo(Subtarget.is64Bit()) {
InstrInfo(*this), JITInfo(*this), TLInfo(*this), ELFWriterInfo(*this) {
DefRelocModel = getRelocationModel();
// FIXME: Correctly select PIC model for Win64 stuff
if (getRelocationModel() == Reloc::Default) {