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llvm-project/llvm/lib/CodeGen/MachOWriter.cpp

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//===-- MachOWriter.cpp - Target-independent Mach-O Writer code -----------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements the target-independent Mach-O writer. This file writes
// out the Mach-O file in the following order:
//
// #1 FatHeader (universal-only)
// #2 FatArch (universal-only, 1 per universal arch)
// Per arch:
// #3 Header
// #4 Load Commands
// #5 Sections
// #6 Relocations
// #7 Symbols
// #8 Strings
//
//===----------------------------------------------------------------------===//
#include "MachO.h"
#include "MachOWriter.h"
#include "MachOCodeEmitter.h"
#include "llvm/Constants.h"
#include "llvm/DerivedTypes.h"
#include "llvm/Module.h"
#include "llvm/PassManager.h"
#include "llvm/Target/TargetAsmInfo.h"
#include "llvm/Target/TargetData.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/Target/TargetMachOWriterInfo.h"
#include "llvm/Support/Mangler.h"
#include "llvm/Support/OutputBuffer.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/raw_ostream.h"
namespace llvm {
/// AddMachOWriter - Concrete function to add the Mach-O writer to the function
/// pass manager.
ObjectCodeEmitter *AddMachOWriter(PassManagerBase &PM,
raw_ostream &O,
TargetMachine &TM) {
MachOWriter *MOW = new MachOWriter(O, TM);
PM.add(MOW);
return MOW->getObjectCodeEmitter();
}
//===----------------------------------------------------------------------===//
// MachOWriter Implementation
//===----------------------------------------------------------------------===//
char MachOWriter::ID = 0;
MachOWriter::MachOWriter(raw_ostream &o, TargetMachine &tm)
: MachineFunctionPass(&ID), O(o), TM(tm) {
is64Bit = TM.getTargetData()->getPointerSizeInBits() == 64;
isLittleEndian = TM.getTargetData()->isLittleEndian();
TAI = TM.getTargetAsmInfo();
// Create the machine code emitter object for this target.
MachOCE = new MachOCodeEmitter(*this, *getTextSection(true));
}
MachOWriter::~MachOWriter() {
delete MachOCE;
}
bool MachOWriter::doInitialization(Module &M) {
// Set the magic value, now that we know the pointer size and endianness
Header.setMagic(isLittleEndian, is64Bit);
// Set the file type
// FIXME: this only works for object files, we do not support the creation
// of dynamic libraries or executables at this time.
Header.filetype = MachOHeader::MH_OBJECT;
Mang = new Mangler(M);
return false;
}
bool MachOWriter::runOnMachineFunction(MachineFunction &MF) {
return false;
}
/// doFinalization - Now that the module has been completely processed, emit
/// the Mach-O file to 'O'.
bool MachOWriter::doFinalization(Module &M) {
// FIXME: we don't handle debug info yet, we should probably do that.
// Okay, the.text section has been completed, build the .data, .bss, and
// "common" sections next.
for (Module::global_iterator I = M.global_begin(), E = M.global_end();
I != E; ++I)
EmitGlobal(I);
// Emit the header and load commands.
EmitHeaderAndLoadCommands();
// Emit the various sections and their relocation info.
EmitSections();
EmitRelocations();
// Write the symbol table and the string table to the end of the file.
O.write((char*)&SymT[0], SymT.size());
O.write((char*)&StrT[0], StrT.size());
// We are done with the abstract symbols.
SectionList.clear();
SymbolTable.clear();
DynamicSymbolTable.clear();
// Release the name mangler object.
delete Mang; Mang = 0;
return false;
}
// getConstSection - Get constant section for Constant 'C'
MachOSection *MachOWriter::getConstSection(Constant *C) {
const ConstantArray *CVA = dyn_cast<ConstantArray>(C);
if (CVA && CVA->isCString())
return getSection("__TEXT", "__cstring",
MachOSection::S_CSTRING_LITERALS);
const Type *Ty = C->getType();
if (Ty->isPrimitiveType() || Ty->isInteger()) {
unsigned Size = TM.getTargetData()->getTypeAllocSize(Ty);
switch(Size) {
default: break; // Fall through to __TEXT,__const
case 4:
return getSection("__TEXT", "__literal4",
MachOSection::S_4BYTE_LITERALS);
case 8:
return getSection("__TEXT", "__literal8",
MachOSection::S_8BYTE_LITERALS);
case 16:
return getSection("__TEXT", "__literal16",
MachOSection::S_16BYTE_LITERALS);
}
}
return getSection("__TEXT", "__const");
}
// getJumpTableSection - Select the Jump Table section
MachOSection *MachOWriter::getJumpTableSection() {
if (TM.getRelocationModel() == Reloc::PIC_)
return getTextSection(false);
else
return getSection("__TEXT", "__const");
}
// getSection - Return the section with the specified name, creating a new
// section if one does not already exist.
MachOSection *MachOWriter::getSection(const std::string &seg,
const std::string &sect,
unsigned Flags /* = 0 */ ) {
MachOSection *MOS = SectionLookup[seg+sect];
if (MOS) return MOS;
MOS = new MachOSection(seg, sect);
SectionList.push_back(MOS);
MOS->Index = SectionList.size();
MOS->flags = MachOSection::S_REGULAR | Flags;
SectionLookup[seg+sect] = MOS;
return MOS;
}
// getTextSection - Return text section with different flags for code/data
MachOSection *MachOWriter::getTextSection(bool isCode /* = true */ ) {
if (isCode)
return getSection("__TEXT", "__text",
MachOSection::S_ATTR_PURE_INSTRUCTIONS |
MachOSection::S_ATTR_SOME_INSTRUCTIONS);
else
return getSection("__TEXT", "__text");
}
MachOSection *MachOWriter::getBSSSection() {
return getSection("__DATA", "__bss", MachOSection::S_ZEROFILL);
}
// GetJTRelocation - Get a relocation a new BB relocation based
// on target information.
MachineRelocation MachOWriter::GetJTRelocation(unsigned Offset,
MachineBasicBlock *MBB) const {
return TM.getMachOWriterInfo()->GetJTRelocation(Offset, MBB);
}
// GetTargetRelocation - Returns the number of relocations.
unsigned MachOWriter::GetTargetRelocation(MachineRelocation &MR,
unsigned FromIdx, unsigned ToAddr,
unsigned ToIndex, OutputBuffer &RelocOut,
OutputBuffer &SecOut, bool Scattered,
bool Extern) {
return TM.getMachOWriterInfo()->GetTargetRelocation(MR, FromIdx, ToAddr,
ToIndex, RelocOut,
SecOut, Scattered,
Extern);
}
void MachOWriter::AddSymbolToSection(MachOSection *Sec, GlobalVariable *GV) {
const Type *Ty = GV->getType()->getElementType();
unsigned Size = TM.getTargetData()->getTypeAllocSize(Ty);
unsigned Align = TM.getTargetData()->getPreferredAlignment(GV);
// Reserve space in the .bss section for this symbol while maintaining the
// desired section alignment, which must be at least as much as required by
// this symbol.
OutputBuffer SecDataOut(Sec->getData(), is64Bit, isLittleEndian);
if (Align) {
Align = Log2_32(Align);
Sec->align = std::max(unsigned(Sec->align), Align);
Sec->emitAlignment(Sec->align);
}
// Globals without external linkage apparently do not go in the symbol table.
if (!GV->hasLocalLinkage()) {
MachOSym Sym(GV, Mang->getMangledName(GV), Sec->Index, TAI);
Sym.n_value = Sec->size();
SymbolTable.push_back(Sym);
}
// Record the offset of the symbol, and then allocate space for it.
// FIXME: remove when we have unified size + output buffer
// Now that we know what section the GlovalVariable is going to be emitted
// into, update our mappings.
// FIXME: We may also need to update this when outputting non-GlobalVariable
// GlobalValues such as functions.
GVSection[GV] = Sec;
GVOffset[GV] = Sec->size();
// Allocate space in the section for the global.
for (unsigned i = 0; i < Size; ++i)
SecDataOut.outbyte(0);
}
void MachOWriter::EmitGlobal(GlobalVariable *GV) {
const Type *Ty = GV->getType()->getElementType();
unsigned Size = TM.getTargetData()->getTypeAllocSize(Ty);
bool NoInit = !GV->hasInitializer();
// If this global has a zero initializer, it is part of the .bss or common
// section.
if (NoInit || GV->getInitializer()->isNullValue()) {
// 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 (NoInit || GV->hasLinkOnceLinkage() || GV->hasWeakLinkage() ||
GV->hasCommonLinkage()) {
MachOSym ExtOrCommonSym(GV, Mang->getMangledName(GV),
MachOSym::NO_SECT, TAI);
// For undefined (N_UNDF) external (N_EXT) types, n_value is the size in
// bytes of the symbol.
ExtOrCommonSym.n_value = Size;
SymbolTable.push_back(ExtOrCommonSym);
// Remember that we've seen this symbol
GVOffset[GV] = Size;
return;
}
// Otherwise, this symbol is part of the .bss section.
MachOSection *BSS = getBSSSection();
AddSymbolToSection(BSS, GV);
return;
}
// Scalar read-only data goes in a literal section if the scalar is 4, 8, or
// 16 bytes, or a cstring. Other read only data goes into a regular const
// section. Read-write data goes in the data section.
MachOSection *Sec = GV->isConstant() ? getConstSection(GV->getInitializer()) :
getDataSection();
AddSymbolToSection(Sec, GV);
InitMem(GV->getInitializer(), GVOffset[GV], TM.getTargetData(), Sec);
}
void MachOWriter::EmitHeaderAndLoadCommands() {
// Step #0: Fill in the segment load command size, since we need it to figure
// out the rest of the header fields
MachOSegment SEG("", is64Bit);
SEG.nsects = SectionList.size();
SEG.cmdsize = SEG.cmdSize(is64Bit) +
SEG.nsects * SectionList[0]->cmdSize(is64Bit);
// Step #1: calculate the number of load commands. We always have at least
// one, for the LC_SEGMENT load command, plus two for the normal
// and dynamic symbol tables, if there are any symbols.
Header.ncmds = SymbolTable.empty() ? 1 : 3;
// Step #2: calculate the size of the load commands
Header.sizeofcmds = SEG.cmdsize;
if (!SymbolTable.empty())
Header.sizeofcmds += SymTab.cmdsize + DySymTab.cmdsize;
// Step #3: write the header to the file
// Local alias to shortenify coming code.
std::vector<unsigned char> &FH = Header.HeaderData;
OutputBuffer FHOut(FH, is64Bit, isLittleEndian);
FHOut.outword(Header.magic);
FHOut.outword(TM.getMachOWriterInfo()->getCPUType());
FHOut.outword(TM.getMachOWriterInfo()->getCPUSubType());
FHOut.outword(Header.filetype);
FHOut.outword(Header.ncmds);
FHOut.outword(Header.sizeofcmds);
FHOut.outword(Header.flags);
if (is64Bit)
FHOut.outword(Header.reserved);
// Step #4: Finish filling in the segment load command and write it out
for (std::vector<MachOSection*>::iterator I = SectionList.begin(),
E = SectionList.end(); I != E; ++I)
SEG.filesize += (*I)->size();
SEG.vmsize = SEG.filesize;
SEG.fileoff = Header.cmdSize(is64Bit) + Header.sizeofcmds;
FHOut.outword(SEG.cmd);
FHOut.outword(SEG.cmdsize);
FHOut.outstring(SEG.segname, 16);
FHOut.outaddr(SEG.vmaddr);
FHOut.outaddr(SEG.vmsize);
FHOut.outaddr(SEG.fileoff);
FHOut.outaddr(SEG.filesize);
FHOut.outword(SEG.maxprot);
FHOut.outword(SEG.initprot);
FHOut.outword(SEG.nsects);
FHOut.outword(SEG.flags);
// Step #5: Finish filling in the fields of the MachOSections
uint64_t currentAddr = 0;
for (std::vector<MachOSection*>::iterator I = SectionList.begin(),
E = SectionList.end(); I != E; ++I) {
MachOSection *MOS = *I;
MOS->addr = currentAddr;
MOS->offset = currentAddr + SEG.fileoff;
// FIXME: do we need to do something with alignment here?
currentAddr += MOS->size();
}
// Step #6: Emit the symbol table to temporary buffers, so that we know the
// size of the string table when we write the next load command. This also
// sorts and assigns indices to each of the symbols, which is necessary for
// emitting relocations to externally-defined objects.
BufferSymbolAndStringTable();
// Step #7: Calculate the number of relocations for each section and write out
// the section commands for each section
currentAddr += SEG.fileoff;
for (std::vector<MachOSection*>::iterator I = SectionList.begin(),
E = SectionList.end(); I != E; ++I) {
MachOSection *MOS = *I;
// Convert the relocations to target-specific relocations, and fill in the
// relocation offset for this section.
CalculateRelocations(*MOS);
MOS->reloff = MOS->nreloc ? currentAddr : 0;
currentAddr += MOS->nreloc * 8;
// write the finalized section command to the output buffer
FHOut.outstring(MOS->sectname, 16);
FHOut.outstring(MOS->segname, 16);
FHOut.outaddr(MOS->addr);
FHOut.outaddr(MOS->size());
FHOut.outword(MOS->offset);
FHOut.outword(MOS->align);
FHOut.outword(MOS->reloff);
FHOut.outword(MOS->nreloc);
FHOut.outword(MOS->flags);
FHOut.outword(MOS->reserved1);
FHOut.outword(MOS->reserved2);
if (is64Bit)
FHOut.outword(MOS->reserved3);
}
// Step #8: Emit LC_SYMTAB/LC_DYSYMTAB load commands
SymTab.symoff = currentAddr;
SymTab.nsyms = SymbolTable.size();
SymTab.stroff = SymTab.symoff + SymT.size();
SymTab.strsize = StrT.size();
FHOut.outword(SymTab.cmd);
FHOut.outword(SymTab.cmdsize);
FHOut.outword(SymTab.symoff);
FHOut.outword(SymTab.nsyms);
FHOut.outword(SymTab.stroff);
FHOut.outword(SymTab.strsize);
// FIXME: set DySymTab fields appropriately
// We should probably just update these in BufferSymbolAndStringTable since
// thats where we're partitioning up the different kinds of symbols.
FHOut.outword(DySymTab.cmd);
FHOut.outword(DySymTab.cmdsize);
FHOut.outword(DySymTab.ilocalsym);
FHOut.outword(DySymTab.nlocalsym);
FHOut.outword(DySymTab.iextdefsym);
FHOut.outword(DySymTab.nextdefsym);
FHOut.outword(DySymTab.iundefsym);
FHOut.outword(DySymTab.nundefsym);
FHOut.outword(DySymTab.tocoff);
FHOut.outword(DySymTab.ntoc);
FHOut.outword(DySymTab.modtaboff);
FHOut.outword(DySymTab.nmodtab);
FHOut.outword(DySymTab.extrefsymoff);
FHOut.outword(DySymTab.nextrefsyms);
FHOut.outword(DySymTab.indirectsymoff);
FHOut.outword(DySymTab.nindirectsyms);
FHOut.outword(DySymTab.extreloff);
FHOut.outword(DySymTab.nextrel);
FHOut.outword(DySymTab.locreloff);
FHOut.outword(DySymTab.nlocrel);
O.write((char*)&FH[0], FH.size());
}
/// EmitSections - Now that we have constructed the file header and load
/// commands, emit the data for each section to the file.
void MachOWriter::EmitSections() {
for (std::vector<MachOSection*>::iterator I = SectionList.begin(),
E = SectionList.end(); I != E; ++I)
// Emit the contents of each section
if ((*I)->size())
O.write((char*)&(*I)->getData()[0], (*I)->size());
}
/// EmitRelocations - emit relocation data from buffer.
void MachOWriter::EmitRelocations() {
for (std::vector<MachOSection*>::iterator I = SectionList.begin(),
E = SectionList.end(); I != E; ++I)
// Emit the relocation entry data for each section.
if ((*I)->RelocBuffer.size())
O.write((char*)&(*I)->RelocBuffer[0], (*I)->RelocBuffer.size());
}
/// BufferSymbolAndStringTable - Sort the symbols we encountered and assign them
/// each a string table index so that they appear in the correct order in the
/// output file.
void MachOWriter::BufferSymbolAndStringTable() {
// The order of the symbol table is:
// 1. local symbols
// 2. defined external symbols (sorted by name)
// 3. undefined external symbols (sorted by name)
// Before sorting the symbols, check the PendingGlobals for any undefined
// globals that need to be put in the symbol table.
for (std::vector<GlobalValue*>::iterator I = PendingGlobals.begin(),
E = PendingGlobals.end(); I != E; ++I) {
if (GVOffset[*I] == 0 && GVSection[*I] == 0) {
MachOSym UndfSym(*I, Mang->getMangledName(*I), MachOSym::NO_SECT, TAI);
SymbolTable.push_back(UndfSym);
GVOffset[*I] = -1;
}
}
// Sort the symbols by name, so that when we partition the symbols by scope
// of definition, we won't have to sort by name within each partition.
std::sort(SymbolTable.begin(), SymbolTable.end(), MachOSym::SymCmp());
// Parition the symbol table entries so that all local symbols come before
// all symbols with external linkage. { 1 | 2 3 }
std::partition(SymbolTable.begin(), SymbolTable.end(),
MachOSym::PartitionByLocal);
// Advance iterator to beginning of external symbols and partition so that
// all external symbols defined in this module come before all external
// symbols defined elsewhere. { 1 | 2 | 3 }
for (std::vector<MachOSym>::iterator I = SymbolTable.begin(),
E = SymbolTable.end(); I != E; ++I) {
if (!MachOSym::PartitionByLocal(*I)) {
std::partition(I, E, MachOSym::PartitionByDefined);
break;
}
}
// Calculate the starting index for each of the local, extern defined, and
// undefined symbols, as well as the number of each to put in the LC_DYSYMTAB
// load command.
for (std::vector<MachOSym>::iterator I = SymbolTable.begin(),
E = SymbolTable.end(); I != E; ++I) {
if (MachOSym::PartitionByLocal(*I)) {
++DySymTab.nlocalsym;
++DySymTab.iextdefsym;
++DySymTab.iundefsym;
} else if (MachOSym::PartitionByDefined(*I)) {
++DySymTab.nextdefsym;
++DySymTab.iundefsym;
} else {
++DySymTab.nundefsym;
}
}
// Write out a leading zero byte when emitting string table, for n_strx == 0
// which means an empty string.
OutputBuffer StrTOut(StrT, is64Bit, isLittleEndian);
StrTOut.outbyte(0);
// The order of the string table is:
// 1. strings for external symbols
// 2. strings for local symbols
// Since this is the opposite order from the symbol table, which we have just
// sorted, we can walk the symbol table backwards to output the string table.
for (std::vector<MachOSym>::reverse_iterator I = SymbolTable.rbegin(),
E = SymbolTable.rend(); I != E; ++I) {
if (I->GVName == "") {
I->n_strx = 0;
} else {
I->n_strx = StrT.size();
StrTOut.outstring(I->GVName, I->GVName.length()+1);
}
}
OutputBuffer SymTOut(SymT, is64Bit, isLittleEndian);
unsigned index = 0;
for (std::vector<MachOSym>::iterator I = SymbolTable.begin(),
E = SymbolTable.end(); I != E; ++I, ++index) {
// Add the section base address to the section offset in the n_value field
// to calculate the full address.
// FIXME: handle symbols where the n_value field is not the address
GlobalValue *GV = const_cast<GlobalValue*>(I->GV);
if (GV && GVSection[GV])
I->n_value += GVSection[GV]->addr;
if (GV && (GVOffset[GV] == -1))
GVOffset[GV] = index;
// Emit nlist to buffer
SymTOut.outword(I->n_strx);
SymTOut.outbyte(I->n_type);
SymTOut.outbyte(I->n_sect);
SymTOut.outhalf(I->n_desc);
SymTOut.outaddr(I->n_value);
}
}
/// CalculateRelocations - For each MachineRelocation in the current section,
/// calculate the index of the section containing the object to be relocated,
/// and the offset into that section. From this information, create the
/// appropriate target-specific MachORelocation type and add buffer it to be
/// written out after we are finished writing out sections.
void MachOWriter::CalculateRelocations(MachOSection &MOS) {
std::vector<MachineRelocation> Relocations = MOS.getRelocations();
for (unsigned i = 0, e = Relocations.size(); i != e; ++i) {
MachineRelocation &MR = Relocations[i];
unsigned TargetSection = MR.getConstantVal();
unsigned TargetAddr = 0;
unsigned TargetIndex = 0;
// This is a scattered relocation entry if it points to a global value with
// a non-zero offset.
bool Scattered = false;
bool Extern = false;
// Since we may not have seen the GlobalValue we were interested in yet at
// the time we emitted the relocation for it, fix it up now so that it
// points to the offset into the correct section.
if (MR.isGlobalValue()) {
GlobalValue *GV = MR.getGlobalValue();
MachOSection *MOSPtr = GVSection[GV];
intptr_t Offset = GVOffset[GV];
// If we have never seen the global before, it must be to a symbol
// defined in another module (N_UNDF).
if (!MOSPtr) {
// FIXME: need to append stub suffix
Extern = true;
TargetAddr = 0;
TargetIndex = GVOffset[GV];
} else {
Scattered = TargetSection != 0;
TargetSection = MOSPtr->Index;
}
MR.setResultPointer((void*)Offset);
}
// If the symbol is locally defined, pass in the address of the section and
// the section index to the code which will generate the target relocation.
if (!Extern) {
MachOSection &To = *SectionList[TargetSection - 1];
TargetAddr = To.addr;
TargetIndex = To.Index;
}
OutputBuffer RelocOut(MOS.RelocBuffer, is64Bit, isLittleEndian);
OutputBuffer SecOut(MOS.getData(), is64Bit, isLittleEndian);
MOS.nreloc += GetTargetRelocation(MR, MOS.Index, TargetAddr, TargetIndex,
RelocOut, SecOut, Scattered, Extern);
}
}
// InitMem - Write the value of a Constant to the specified memory location,
// converting it into bytes and relocations.
void MachOWriter::InitMem(const Constant *C, uintptr_t Offset,
const TargetData *TD, MachOSection* mos) {
typedef std::pair<const Constant*, intptr_t> CPair;
std::vector<CPair> WorkList;
uint8_t *Addr = &mos->getData()[0];
WorkList.push_back(CPair(C,(intptr_t)Addr + Offset));
intptr_t ScatteredOffset = 0;
while (!WorkList.empty()) {
const Constant *PC = WorkList.back().first;
intptr_t PA = WorkList.back().second;
WorkList.pop_back();
if (isa<UndefValue>(PC)) {
continue;
} else if (const ConstantVector *CP = dyn_cast<ConstantVector>(PC)) {
unsigned ElementSize =
TD->getTypeAllocSize(CP->getType()->getElementType());
for (unsigned i = 0, e = CP->getNumOperands(); i != e; ++i)
WorkList.push_back(CPair(CP->getOperand(i), PA+i*ElementSize));
} else if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(PC)) {
//
// FIXME: Handle ConstantExpression. See EE::getConstantValue()
//
switch (CE->getOpcode()) {
case Instruction::GetElementPtr: {
SmallVector<Value*, 8> Indices(CE->op_begin()+1, CE->op_end());
ScatteredOffset = TD->getIndexedOffset(CE->getOperand(0)->getType(),
&Indices[0], Indices.size());
WorkList.push_back(CPair(CE->getOperand(0), PA));
break;
}
case Instruction::Add:
default:
cerr << "ConstantExpr not handled as global var init: " << *CE << "\n";
llvm_unreachable(0);
}
} else if (PC->getType()->isSingleValueType()) {
unsigned char *ptr = (unsigned char *)PA;
switch (PC->getType()->getTypeID()) {
case Type::IntegerTyID: {
unsigned NumBits = cast<IntegerType>(PC->getType())->getBitWidth();
uint64_t val = cast<ConstantInt>(PC)->getZExtValue();
if (NumBits <= 8)
ptr[0] = val;
else if (NumBits <= 16) {
if (TD->isBigEndian())
val = ByteSwap_16(val);
ptr[0] = val;
ptr[1] = val >> 8;
} else if (NumBits <= 32) {
if (TD->isBigEndian())
val = ByteSwap_32(val);
ptr[0] = val;
ptr[1] = val >> 8;
ptr[2] = val >> 16;
ptr[3] = val >> 24;
} else if (NumBits <= 64) {
if (TD->isBigEndian())
val = ByteSwap_64(val);
ptr[0] = val;
ptr[1] = val >> 8;
ptr[2] = val >> 16;
ptr[3] = val >> 24;
ptr[4] = val >> 32;
ptr[5] = val >> 40;
ptr[6] = val >> 48;
ptr[7] = val >> 56;
} else {
llvm_unreachable("Not implemented: bit widths > 64");
}
break;
}
case Type::FloatTyID: {
uint32_t val = cast<ConstantFP>(PC)->getValueAPF().bitcastToAPInt().
getZExtValue();
if (TD->isBigEndian())
val = ByteSwap_32(val);
ptr[0] = val;
ptr[1] = val >> 8;
ptr[2] = val >> 16;
ptr[3] = val >> 24;
break;
}
case Type::DoubleTyID: {
uint64_t val = cast<ConstantFP>(PC)->getValueAPF().bitcastToAPInt().
getZExtValue();
if (TD->isBigEndian())
val = ByteSwap_64(val);
ptr[0] = val;
ptr[1] = val >> 8;
ptr[2] = val >> 16;
ptr[3] = val >> 24;
ptr[4] = val >> 32;
ptr[5] = val >> 40;
ptr[6] = val >> 48;
ptr[7] = val >> 56;
break;
}
case Type::PointerTyID:
if (isa<ConstantPointerNull>(PC))
memset(ptr, 0, TD->getPointerSize());
else if (const GlobalValue* GV = dyn_cast<GlobalValue>(PC)) {
// FIXME: what about function stubs?
mos->addRelocation(MachineRelocation::getGV(PA-(intptr_t)Addr,
MachineRelocation::VANILLA,
const_cast<GlobalValue*>(GV),
ScatteredOffset));
ScatteredOffset = 0;
} else
llvm_unreachable("Unknown constant pointer type!");
break;
default:
std::string msg;
raw_string_ostream Msg(msg);
Msg << "ERROR: Constant unimp for type: " << *PC->getType();
llvm_report_error(Msg.str());
}
} else if (isa<ConstantAggregateZero>(PC)) {
memset((void*)PA, 0, (size_t)TD->getTypeAllocSize(PC->getType()));
} else if (const ConstantArray *CPA = dyn_cast<ConstantArray>(PC)) {
unsigned ElementSize =
TD->getTypeAllocSize(CPA->getType()->getElementType());
for (unsigned i = 0, e = CPA->getNumOperands(); i != e; ++i)
WorkList.push_back(CPair(CPA->getOperand(i), PA+i*ElementSize));
} else if (const ConstantStruct *CPS = dyn_cast<ConstantStruct>(PC)) {
const StructLayout *SL =
TD->getStructLayout(cast<StructType>(CPS->getType()));
for (unsigned i = 0, e = CPS->getNumOperands(); i != e; ++i)
WorkList.push_back(CPair(CPS->getOperand(i),
PA+SL->getElementOffset(i)));
} else {
cerr << "Bad Type: " << *PC->getType() << "\n";
llvm_unreachable("Unknown constant type to initialize memory with!");
}
}
}
//===----------------------------------------------------------------------===//
// MachOSym Implementation
//===----------------------------------------------------------------------===//
MachOSym::MachOSym(const GlobalValue *gv, std::string name, uint8_t sect,
const TargetAsmInfo *TAI) :
GV(gv), n_strx(0), n_type(sect == NO_SECT ? N_UNDF : N_SECT), n_sect(sect),
n_desc(0), n_value(0) {
switch (GV->getLinkage()) {
default:
llvm_unreachable("Unexpected linkage type!");
break;
case GlobalValue::WeakAnyLinkage:
case GlobalValue::WeakODRLinkage:
case GlobalValue::LinkOnceAnyLinkage:
case GlobalValue::LinkOnceODRLinkage:
case GlobalValue::CommonLinkage:
assert(!isa<Function>(gv) && "Unexpected linkage type for Function!");
case GlobalValue::ExternalLinkage:
GVName = TAI->getGlobalPrefix() + name;
n_type |= GV->hasHiddenVisibility() ? N_PEXT : N_EXT;
break;
case GlobalValue::PrivateLinkage:
GVName = TAI->getPrivateGlobalPrefix() + name;
break;
case GlobalValue::LinkerPrivateLinkage:
GVName = TAI->getLessPrivateGlobalPrefix() + name;
break;
case GlobalValue::InternalLinkage:
GVName = TAI->getGlobalPrefix() + name;
break;
}
}
} // end namespace llvm
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